\input texinfo
@comment %**start of header
@setfilename auctex.info
@include version.texi
@settitle AUCTeX @value{VERSION}
@c footnotestyle separate
@c paragraphindent 2
@comment %**end of header
@include macros.texi
@copying
This manual is for @AUCTeX{}
(version @value{VERSION} from @value{UPDATED}),
a sophisticated @TeX{} environment for Emacs.

Copyright @copyright{} 1992-1995, 2001, 2002, 2004-2021
Free Software Foundation, Inc.

@quotation
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with no
Invariant Sections, no Front-Cover Texts and no Back-Cover Texts.  A
copy of the license is included in the section entitled ``GNU Free
Documentation License.''
@end quotation
@end copying

@dircategory Emacs
@direntry
* AUCTeX: (auctex).     A sophisticated TeX environment for Emacs.
@end direntry
@dircategory TeX
@direntry
* AUCTeX: (auctex).     A sophisticated TeX environment for Emacs.
@end direntry

@iftex
@tolerance 10000 @emergencystretch 3em
@end iftex

@finalout
@titlepage
@title @AUCTeX{}
@subtitle A sophisticated @TeX{} environment for Emacs
@subtitle Version @value{VERSION}, @value{UPDATED}
@author Kresten Krab Thorup
@author Per Abrahamsen
@author David Kastrup and others
@page
@vskip 0pt plus 1filll
@insertcopying
@end titlepage

@c Use @ifinfo _and_ @ifhtml here because Texinfo 3 cannot cope with
@c @ifnottex around a top node.
@ifinfo
@node top
@top @AUCTeX{}

This manual may be copied under the conditions spelled out in
@ref{Copying this Manual}.

@end ifinfo
@ifhtml
@node top
@top @AUCTeX{}
@insertcopying
@end ifhtml

@contents

@iftex
@unnumbered Executive Summary
@end iftex

@AUCTeX{} is an integrated environment for editing @LaTeX{}, @ConTeXt{},
doc@TeX{}, Texinfo, and @TeX{} files.

Although @AUCTeX{} contains a large number of features, there are no
reasons to despair.  You can continue to write @TeX{} and @LaTeX{}
documents the way you are used to, and only start using the multiple
features in small steps.  @AUCTeX{} is not monolithic, each feature
described in this manual is useful by itself, but together they provide
an environment where you will make very few @LaTeX{} errors, and makes
it easy to find the errors that may slip through anyway.

It is a good idea to make a printout of @AUCTeX{}'s reference card
@file{tex-ref.tex} or one of its typeset versions.

If you want to make @AUCTeX{} aware of style files and multi-file
documents right away, insert the following in your init file (usually
@file{~/.emacs.d/init.el}).

@lisp
(setq TeX-auto-save t)
(setq TeX-parse-self t)
(setq-default TeX-master nil)
@end lisp

Another thing you should enable is Ref@TeX{}, a comprehensive solution
for managing cross references, bibliographies, indices, document
navigation and a few other things.  (@xref{Installation,,,reftex,The
Ref@TeX{} manual}.)

For detailed information about the @previewlatex{} subsystem of
@AUCTeX{}, see @ref{Top,,Introduction,preview-latex,The @previewlatex{}
Manual}.

There is a mailing list for general discussion about @AUCTeX{}: write a
mail with ``subscribe'' in the subject to
@email{auctex-request@@gnu.org} to join it.  Send contributions to
@email{auctex@@gnu.org}.

Bug reports should go to @email{bug-auctex@@gnu.org}, suggestions for
new features, and pleas for help should go to either
@email{auctex-devel@@gnu.org} (the @AUCTeX{} developers), or to
@email{auctex@@gnu.org} if they might have general interest.  Please use
the command @kbd{M-x TeX-submit-bug-report @key{RET}} to report bugs if
possible.  You can subscribe to a low-volume announcement list by
sending ``subscribe'' in the subject of a mail to
@email{info-auctex-request@@gnu.org}.

@menu
* Copying::                     Copying
* Introduction::                Introduction to @AUCTeX{}
* Editing::                     Editing the Document Source
* Display::                     Controlling Screen Display
* Processing::                  Starting Processors, Viewers and Other Programs
* Customization::               Customization and Extension
* Appendices::                  Copying, Changes, Development, FAQ, Texinfo mode
* Indices::                     Indices

@detailmenu
 --- The Detailed Node Listing ---

Introduction

* Summary::                     Overview of @AUCTeX{}
* Installation::                Installing @AUCTeX{}
* Quick Start::                 Quick Start

Editing the Document Source

* Quotes::                      Inserting double quotes
* Font Specifiers::             Inserting Font Specifiers
* Sectioning::                  Inserting chapters, sections, etc.
* Environments::                Inserting Environment Templates
* Mathematics::                 Entering Mathematics
* Completion::                  Completion of macros
* Commenting::                  Commenting text
* Indenting::                   Reflecting syntactic constructs with whitespace
* Filling::                     Automatic and manual line breaking

Inserting Environment Templates

* Equations::                   Equations
* Floats::                      Floats
* Itemize-like::                Itemize-like Environments
* Tabular-like::                Tabular-like Environments
* Customizing Environments::    Customizing Environments

Controlling Screen Display

* Font Locking::                Font Locking
* Folding::                     Folding Macros and Environments
* Outline::                     Outlining the Document
* Narrowing::                   Restricting display and editing to a portion of the buffer
* Prettifying::                 Displaying Greek and math macros as Unicode characters

Font Locking

* Fontification of macros::     Fontification of macros
* Fontification of quotes::     Fontification of quotes
* Fontification of math::       Fontification of math constructs
* Verbatim content::            Verbatim macros and environments
* Faces::                       Faces used by font-latex
* Known problems::              Known fontification problems

Starting Processors, Viewers and Other Programs

* Commands::                    Invoking external commands.
* Viewing::                     Invoking external viewers.
* Debugging::                   Debugging @TeX{} and @LaTeX{} output.
* Checking::                    Checking the document.
* Control::                     Controlling the processes.
* Cleaning::                    Cleaning intermediate and output files.
* Documentation::               Documentation about macros and packages.

Viewing the Formatted Output

* Starting Viewers::            Starting viewers
* I/O Correlation::             Forward and inverse search

Catching the errors

* Ignoring warnings::           Controlling warnings to be reported
* Error overview::              List of all errors and warnings

Customization and Extension

* Multifile::                   Multifile Documents
* Parsing Files::               Automatic Parsing of @TeX{} Files
* Internationalization::        Language Support
* Automatic::                   Automatic Customization
* Style Files::                 Writing Your Own Style Support

Language Support

* European::                    Using @AUCTeX{} with European Languages
* Japanese::                    Using @AUCTeX{} with Japanese

Automatic Customization

* Automatic Global::            Automatic Customization for the Site
* Automatic Private::           Automatic Customization for a User
* Automatic Local::             Automatic Customization for a Directory

Writing Your Own Style Support

* Simple Style::                A Simple Style File
* Adding Macros::               Adding Support for Macros
* Adding Environments::         Adding Support for Environments
* Adding Other::                Adding or Examining Other Information
* Hacking the Parser::          Automatic Extraction of New Things

Copying, Changes, Development, FAQ

* Copying this Manual::         
* Changes::                     
* Development::                 
* FAQ::                         
* Texinfo mode::                

Copying this Manual

* GNU Free Documentation License:: License for copying this manual.

Indices

* Key Index::                   
* Function Index::              
* Variable Index::              
* Concept Index::               

@end detailmenu
@end menu

@node Copying
@unnumbered Copying
@cindex Copying
@cindex Copyright
@cindex GPL
@cindex General Public License
@cindex License
@cindex Free
@cindex Free software
@cindex Distribution
@cindex Right
@cindex Warranty

@c This text adapted from the Texinfo 2.16 distribution.

@AUCTeX{} primarily consists of Lisp files for Emacs, but
there are also installation scripts and files and @TeX{} support files.
All of those are @dfn{free}; this means that everyone is free to use
them and free to redistribute them on a free basis.  The files of
@AUCTeX{} are not in the public domain; they are copyrighted and there
are restrictions on their distribution, but these restrictions are
designed to permit everything that a good cooperating citizen would want
to do.  What is not allowed is to try to prevent others from further
sharing any version of these programs that they might get from you.

Specifically, we want to make sure that you have the right to give away
copies of the files that constitute @AUCTeX{}, that you receive source
code or else can get it if you want it, that you can change these files
or use pieces of them in new free programs, and that you know you can do
these things.

To make sure that everyone has such rights, we have to forbid you to
deprive anyone else of these rights.  For example, if you distribute
copies of parts of @AUCTeX{}, you must give the recipients all the
rights that you have.  You must make sure that they, too, receive or can
get the source code.  And you must tell them their rights.

Also, for our own protection, we must make certain that everyone finds
out that there is no warranty for @AUCTeX{}.  If any parts are modified
by someone else and passed on, we want their recipients to know that
what they have is not what we distributed, so that any problems
introduced by others will not reflect on our reputation.

The precise conditions of the licenses for the files currently being
distributed as part of @AUCTeX{} are found in the General Public
Licenses that accompany them.  This manual specifically is covered by
the GNU Free Documentation License (@pxref{Copying this Manual}).

@node Introduction
@chapter Introduction

@menu
* Summary::                     Overview of @AUCTeX{}
* Installation::                Installing @AUCTeX{}
* Quick Start::                 Quick Start
@end menu

@lowersections
@include intro.texi

@include install.texi

@include quickstart.texi
@raisesections

@node Editing
@chapter Editing the Document Source

The most commonly used commands/macros of @AUCTeX{} are those which
simply insert templates for often used @TeX{}, @LaTeX{}, or @ConTeXt{}
constructs, like font changes, handling of environments, etc.  These
features are very simple, and easy to learn, and help you avoid mistakes
like mismatched braces, or @samp{\begin@{@}}-@samp{\end@{@}} pairs.

Apart from that this chapter contains a description of some features for
entering more specialized sorts of text, for formatting the source by
indenting and filling and for navigating through the document.

@menu
* Quotes::                      Inserting quotes, dollars, and braces
* Font Specifiers::             Inserting Font Specifiers
* Sectioning::                  Inserting chapters, sections, etc.
* Environments::                Inserting Environment Templates
* Mathematics::                 Entering Mathematics
* Completion::                  Completion of macros
* Marking::                     Marking Environments, Sections, or Texinfo Nodes
* Commenting::                  Commenting text
* Indenting::                   Reflecting syntactic constructs with whitespace
* Filling::                     Automatic and manual line breaking
@end menu

@node Quotes
@section Insertion of Quotes, Dollars, and Braces

@cindex Quotes
@cindex Double quotes
@cindex Braces
@cindex Brackets
@cindex Dollars
@cindex Math mode delimiters
@cindex Matching dollar signs
@cindex Display math mode

@subheading Quotation Marks

In @TeX{}, literal double quotes @samp{"like this"} are seldom used,
instead two single quotes are used @samp{``like this''}.  To help you
insert these efficiently, @AUCTeX{} allows you to continue to press
@kbd{"} to insert two single quotes.  To get a literal double quote,
press @kbd{"} twice.

@deffn Command TeX-insert-quote @var{count}
@kindex "
(@kbd{"}) Insert the appropriate quote marks for @TeX{}.

Inserts the value of @code{TeX-open-quote} (normally @samp{``}) or
@code{TeX-close-quote} (normally @samp{''}) depending on the context.
With prefix argument, always inserts @samp{"} characters.
@end deffn

@defopt TeX-open-quote
String inserted by typing @kbd{"} to open a quotation.
(@xref{European}, for language-specific quotation mark insertion.)
@end defopt

@defopt TeX-close-quote
String inserted by typing @kbd{"} to close a quotation.
(@xref{European}, for language-specific quotation mark insertion.)
@end defopt

@defopt TeX-quote-after-quote
Determines the behavior of @kbd{"}.  If it is non-nil, typing @kbd{"}
will insert a literal double quote.  The respective values of
@code{TeX-open-quote} and @code{TeX-close-quote} will be inserted
after typing @kbd{"} once again.
@end defopt

The @samp{babel} package provides special support for the requirements
of typesetting quotation marks in many different languages.  If you use
this package, either directly or by loading a language-specific style
file, you should also use the special commands for quote insertion
instead of the standard quotes shown above.  @AUCTeX{} is able to
recognize several of these languages and will change quote insertion
accordingly.  @xref{European}, for details about this feature and how to
control it.

@vindex LaTeX-csquotes-open-quote
@vindex LaTeX-csquotes-close-quote
@vindex LaTeX-csquotes-quote-after-quote
In case you are using the @samp{csquotes} package, you should customize
@code{LaTeX-csquotes-open-quote}, @code{LaTeX-csquotes-close-quote} and
@code{LaTeX-csquotes-quote-after-quote}.  The quotation characters will
only be used if both variables---@code{LaTeX-csquotes-open-quote} and
@code{LaTeX-csquotes-close-quote}---are non-empty strings.  But then the
@samp{csquotes}-related values will take precedence over the
language-specific ones.

@subheading Dollar Signs

In @AUCTeX{}, dollar signs should match like they do in @TeX{}.  This
has been partially implemented, we assume dollar signs always match
within a paragraph.  By default, the first @samp{$} you insert in a
paragraph will do nothing special.  The second @samp{$} will match the
first.  This will be indicated by moving the cursor temporarily over the
first dollar sign.

@deffn Command TeX-insert-dollar @var{arg}
@kindex $
(@kbd{$}) Insert dollar sign.

Show matching dollar sign if this dollar sign end the @TeX{} math mode.

With optional @var{arg}, insert that many dollar signs.
@end deffn

@TeX{} and @LaTeX{} users often look for a way to insert inline
equations like @samp{$...$} or @samp{\(...\)} simply typing @kbd{$}.
@AUCTeX{} helps them through the customizable variable
@code{TeX-electric-math}.

@defopt TeX-electric-math
If the variable is non-nil and you type @kbd{$} outside math mode,
@AUCTeX{} will automatically insert the opening and closing symbols for
an inline equation and put the point between them.  The opening symbol
will blink when @code{blink-matching-paren} is non-nil.  If
@code{TeX-electric-math} is nil, typing @kbd{$} simply inserts @samp{$}
at point, this is the default.

Besides @code{nil}, possible values for this variable are @code{(cons
"$" "$")} for @TeX{} inline equations @samp{$...$}, and @code{(cons
"\\(" "\\)")} for @LaTeX{} inline equations @samp{\(...\)}.

If the variable is non-nil and point is inside math mode right between a
couple of single dollars, pressing @kbd{$} will insert another pair of
dollar signs and leave the point between them.  Thus, if
@code{TeX-electric-math} is set to @code{(cons "$" "$")} you can easily
obtain a @TeX{} display equation @samp{$$...$$} by pressing @kbd{$}
twice in a row.  (Note that you should not use double dollar signs in
@LaTeX{} because this practice can lead to wrong spacing in typeset
documents.)

In addition, when the variable is non-nil and there is an active region
outside math mode, typing @kbd{$} will put around the active region
symbols for opening and closing inline equation and keep the region
active, leaving point after the closing symbol.  By pressing repeatedly
@kbd{$} while the region is active you can toggle between an inline
equation, a display equation, and no equation.  To be precise,
@samp{$...$} is replaced by @samp{$$...$$}, whereas @samp{\(...\)} is
replaced by @samp{\[...\]}.
@end defopt

If you want to automatically insert @samp{$...$} in plain @TeX{} files,
and @samp{\(...\)} in @LaTeX{} files by pressing @kbd{$}, add the
following to your init file
@lisp
(add-hook 'plain-TeX-mode-hook
          (lambda () (set (make-local-variable 'TeX-electric-math)
                          (cons "$" "$"))))
(add-hook 'LaTeX-mode-hook
          (lambda () (set (make-local-variable 'TeX-electric-math)
                          (cons "\\(" "\\)"))))
@end lisp

Note that Texinfo mode does nothing special for @kbd{$}.  It inserts
dollar sign(s) just in the same way as the other normal keys do.

@subheading Braces

To avoid unbalanced braces, it is useful to insert them pairwise.  You
can do this by typing @kbd{C-c @{}.

@deffn Command TeX-insert-braces
@kindex C-c @{
(@kbd{C-c @{}) Make a pair of braces and position the cursor
to type inside of them.  If there is an active region, put braces around
it and leave point after the closing brace.
@end deffn

When writing complex math formulas in @LaTeX{} documents, you
sometimes need to adjust the size of braces with pairs of macros like
@samp{\left}-@samp{\right}, @samp{\bigl}-@samp{\bigr} and so on.  You
can avoid unbalanced pairs with the help of @code{TeX-insert-macro},
bound to @kbd{C-c C-m} or @kbd{C-c @key{RET}} (@pxref{Completion}).
If you insert left size adjusting macros such as @samp{\left},
@samp{\bigl} etc.@: with @code{TeX-insert-macro}, it asks for left brace
to use and supplies automatically right size adjusting macros such as
@samp{\right}, @samp{\bigr} etc.@: and corresponding right brace in
addtion to the intended left macro and left brace.

The completion by @code{TeX-insert-macro} also applies when entering
macros such as @samp{\langle}, @samp{\lfloor} and @samp{\lceil}, which
produce the left part of the paired braces.  For example, inserting
@samp{\lfloor} by @kbd{C-c C-m} is immediately followed by the
insertion of @samp{\rfloor}.  In addition, if the point was located
just after @samp{\left} or its friends, the corresponding
@samp{\right} etc.@: will be inserted in front of @samp{\rfloor}.
In both cases, active region is honored.

As a side effect, when @code{LaTeX-math-mode} (@pxref{Mathematics}) is
on, just typing @kbd{`(} inserts not only @samp{\langle}, but also
@samp{\rangle}.

If you do not like such auto completion at all, it can be disabled by a
user option.

@defopt TeX-arg-right-insert-p
If this option is turned off, the automatic supply of the right macros
and braces is suppressed.
@end defopt

@kindex (
@kindex @{
@kindex [
When you edit @LaTeX{} documents, you can enable automatic brace
pairing when typing @kbd{(}, @kbd{@{} and @kbd{[}.

@defopt LaTeX-electric-left-right-brace
If this option is on, just typing @kbd{(}, @kbd{@{} or @kbd{[}
immediately adds the corresponding right brace @samp{)}, @samp{@}} or
@samp{]}.  The point is left after the opening brace.  If there is an
active region, braces are put around it.

They recognize the preceding backslash or size adjusting macros such
as @samp{\left}, @samp{\bigl} etc., so the following completions will
occur:
@itemize @bullet

@item
(when typing single left brace)
@itemize @minus

@item
@samp{(} -> @samp{()}

@item
@samp{@{} -> @samp{@{@}}

@item
@samp{[} -> @samp{[]}
@end itemize

@item
(when typing left brace just after a backslash)
@itemize @minus

@item
@samp{\(} -> @samp{\(\)}

@item
@samp{\@{} -> @samp{\@{\@}}

@item
@samp{\[} -> @samp{\[\]}
@end itemize

@item
(when typing just after @samp{\left} or @samp{\bigl})
@itemize @minus

@item
@samp{\left(} -> @samp{\left(\right)}

@item
@samp{\bigl[} -> @samp{\bigl[\bigr]}
@end itemize

@item
(when typing just after @samp{\Bigl\})
@itemize @minus

@item
@samp{\Bigl\@{} -> @samp{\Bigl\@{\Bigr\@}}

@end itemize

@end itemize

This auto completion feature may be a bit annoying when editing an
already existing @LaTeX{} document.  In that case, use @kbd{C-u 1} or
@kbd{C-q} before typing @kbd{(}, @kbd{@{} or @kbd{[}.  Then no
completion is done and just a single left brace is inserted.  In fact,
with optional prefix @var{arg}, just that many open braces are
inserted without any completion.
@end defopt

@node Font Specifiers
@section Inserting Font Specifiers

@cindex Fonts
@cindex Font macros
@cindex Changing font
@cindex Specifying a font

Perhaps the most used keyboard commands of @AUCTeX{} are the short-cuts
available for easy insertion of font changing macros.

If you give an argument (that is, type @kbd{C-u}) to the font command,
the innermost font will be replaced, i.e.@: the font in the @TeX{} group
around point will be changed.  The following table shows the available
commands, with @code{@point{}} indicating the position where the text
will be inserted.

@table @kbd
@item C-c C-f C-b
@kindex C-c C-f C-b
@cindex @code{\textbf}
Insert @b{bold face} @samp{\textbf@{@point{}@}} text.

@item C-c C-f C-m
@kindex C-c C-f C-m
@cindex @code{\textmd}
Insert @r{medium face} @samp{\textmd@{@point{}@}} text.

@item C-c C-f C-i
@kindex C-c C-f C-i
@cindex @code{\textit}
Insert @i{italics} @samp{\textit@{@point{}@}} text.

@item C-c C-f C-e
@kindex C-c C-f C-e
@cindex @code{\emph}
Insert @emph{emphasized} @samp{\emph@{@point{}@}} text.

@item C-c C-f C-s
@kindex C-c C-f C-s
@cindex @code{\textsl}
Insert @slanted{slanted} @samp{\textsl@{@point{}@}} text.

@item C-c C-f C-r
@kindex C-c C-f C-r
@cindex @code{\textrm}
Insert @r{roman} @samp{\textrm@{@point{}@}} text.

@item C-c C-f C-f
@kindex C-c C-f C-f
@cindex @code{\textsf}
Insert @sansserif{sans serif} @samp{\textsf@{@point{}@}} text.

@item C-c C-f C-t
@kindex C-c C-f C-t
@cindex @code{\texttt}
Insert @t{typewriter} @samp{\texttt@{@point{}@}} text.

@item C-c C-f C-c
@kindex C-c C-f C-c
@cindex @code{\textsc}
Insert @sc{small caps} @samp{\textsc@{@point{}@}} text.

@item C-c C-f C-l
@kindex C-c C-f C-l
@cindex @code{\textulc}
Insert upper lower case @samp{\textulc@{@point{}@}} text.

@item C-c C-f C-w
@kindex C-c C-f C-w
@cindex @code{\textsw}
Insert @sc{swash} @samp{\textsw@{@point{}@}} text.

@item C-c C-f C-n
@kindex C-c C-f C-n
@cindex @code{\textnormal}
Insert normal @samp{\textnormal@{@point{}@}} text.

@item C-c C-f C-d
@kindex C-c C-f C-c
@cindex Deleting fonts
Delete the innermost font specification containing point.

@end table

@deffn Command TeX-font @var{replace} @var{what}
@kindex C-c C-f
(@kbd{C-c C-f}) Insert template for font change command.

If @var{replace} is not nil, replace current font.  @var{what}
determines the font to use, as specified by @code{TeX-font-list}.
@end deffn

@defopt TeX-font-list
List of fonts used by @code{TeX-font}.

Each entry is a list with three elements.  The first element is the
key to activate the font.  The second element is the string to insert
before point, and the third element is the string to insert after
point.  An optional fourth element means always replace if not nil.
@end defopt

@defopt LaTeX-font-list
List of fonts used by @code{TeX-font} in LaTeX mode.  It has the same
structure as @code{TeX-font-list}.
@end defopt

@node Sectioning
@section Inserting chapters, sections, etc.
@cindex Sectioning
@cindex Sections
@cindex Chapters
@cindex @code{\chapter}
@cindex @code{\section}
@cindex @code{\subsection}
@cindex @code{\label}

Insertion of sectioning macros, that is @samp{\chapter},
@samp{\section}, @samp{\subsection}, etc.@: and accompanying
@samp{\label}'s may be eased by using @kbd{C-c C-s}.  This command is
highly customizable, the following describes the default behavior.

When invoking you will be asked for a section macro to insert.  An
appropriate default is automatically selected by @AUCTeX{}, that is
either: at the top of the document; the top level sectioning for that
document style, and any other place: The same as the last occurring
sectioning command.

Next, you will be asked for the actual name of that section, and last
you will be asked for a label to be associated with that section.  The
label will be prefixed by the value specified in
@code{LaTeX-section-hook}.

@deffn Command LaTeX-section @var{arg}
@kindex C-c C-s
(@kbd{C-c C-s}) Insert a sectioning command.

Determine the type of section to be inserted, by the argument
@var{arg}.

@itemize @bullet
@item
If @var{arg} is nil or missing, use the current level.
@item
If @var{arg} is a list (selected by C-u), go downward one level.
@item
If @var{arg} is negative, go up that many levels.
@item
If @var{arg} is positive or zero, use absolute level:
@itemize +
@item
0 : part
@item
1 : chapter
@item
2 : section
@item
3 : subsection
@item
4 : subsubsection
@item
5 : paragraph
@item
6 : subparagraph
@end itemize
@end itemize

The following variables can be set to customize the function.

@vtable @code
@item LaTeX-section-hook
Hooks to be run when inserting a section.
@item LaTeX-section-label
Prefix to all section references.
@end vtable

@end deffn

The precise behavior of @code{LaTeX-section} is defined by the contents
of @code{LaTeX-section-hook}.

@defopt LaTeX-section-hook
List of hooks to run when a new section is inserted.

The following variables are set before the hooks are run

@vtable @code
@item LaTeX-level
Numeric section level, default set by prefix arg to
@code{LaTeX-section}.
@item LaTeX-name
Name of the sectioning command, derived from @code{LaTeX-level}.
@item LaTeX-title
The title of the section, default to an empty string.
@item LaTeX-toc
Entry for the table of contents list, default nil.
@item LaTeX-done-mark
Position of point afterwards, default nil meaning after the inserted
text.
@end vtable

A number of hooks are already defined.  Most likely, you will be able to
get the desired functionality by choosing from these hooks.

@ftable @code
@item LaTeX-section-heading
Query the user about the name of the sectioning command.  Modifies
@code{LaTeX-level} and @code{LaTeX-name}.
@item LaTeX-section-title
Query the user about the title of the section.  Modifies @code{LaTeX-title}.
@item LaTeX-section-toc
Query the user for the toc entry.  Modifies @code{LaTeX-toc}.
@item LaTeX-section-section
Insert @LaTeX{} section command according to @code{LaTeX-name},
@code{LaTeX-title}, and @code{LaTeX-toc}.  If @code{LaTeX-toc} is nil, no
toc entry is inserted.  If @code{LaTeX-toc} or @code{LaTeX-title} are
empty strings, @code{LaTeX-done-mark} will be placed at the point they
should be inserted.
@item LaTeX-section-label
Insert a label after the section command.  Controlled by the variable
@code{LaTeX-section-label}.
@end ftable

To get a full featured @code{LaTeX-section} command, insert

@lisp
(setq LaTeX-section-hook
      '(LaTeX-section-heading
        LaTeX-section-title
        LaTeX-section-toc
        LaTeX-section-section
        LaTeX-section-label))
@end lisp

in your init file such as @file{init.el} or @file{.emacs}.
@end defopt

The behavior of @code{LaTeX-section-label} is determined by the
variable @code{LaTeX-section-label}.

@defopt LaTeX-section-label
Default prefix when asking for a label.

If it is a string, it is used unchanged for all kinds of sections.
If it is nil, no label is inserted.
If it is a list, the list is searched for a member whose car is equal
to the name of the sectioning command being inserted.  The cdr is then
used as the prefix.  If the name is not found, or if the cdr is nil,
no label is inserted.

@cindex Prefix for labels
@cindex Label prefix
@cindex Labels
By default, chapters have a prefix of @samp{cha:} while sections and
subsections have a prefix of @samp{sec:}.  Labels are not automatically
inserted for other types of sections.
@end defopt

@node Environments
@section Inserting Environment Templates
@cindex Environments
@cindex @samp{\begin}
@cindex @samp{\end}

A large apparatus is available that supports insertions of environments,
that is @samp{\begin@{@}} --- @samp{\end@{@}} pairs.

@AUCTeX{} is aware of most of the actual environments available in a
specific document.  This is achieved by examining your
@samp{\documentclass} command, and consulting a precompiled list of
environments available in a large number of styles.

Most of these are described further in the following sections, and you
may easily specify more.  @xref{Customizing Environments}.

You insert an environment with @kbd{C-c C-e}, and select an environment
type.  Depending on the environment, @AUCTeX{} may ask more questions
about the optional parts of the selected environment type.  With
@kbd{C-u C-c C-e} you will change the current environment.

@deffn Command LaTeX-environment @var{arg}
@kindex C-c C-e
(@kbd{C-c C-e})  @AUCTeX{} will prompt you for an environment
to insert.  At this prompt, you may press @key{TAB} or @key{SPC} to
complete a partially written name, and/or to get a list of available
environments.  After selection of a specific environment @AUCTeX{} may
prompt you for further specifications.

If the optional argument @var{arg} is non-nil (i.e.@: you have given a
prefix argument), the current environment is modified and no new
environment is inserted.
@end deffn

@AUCTeX{} helps you adding labels to environments which use them, such
as @samp{equation}, @samp{figure}, @samp{table}, etc@dots{}  When you
insert one of the supported environments with @kbd{C-c C-e}, you will be
automatically prompted for a label.  You can select the prefix to be
used for such environments with the @code{LaTeX-label-alist} variable.
@defopt LaTeX-label-alist
List the prefixes to be used for the label of each supported
environment.

This is an alist whose car is the environment name, and the cdr either
the prefix or a symbol referring to one.

If the name is not found, or if the cdr is nil, no label is
automatically inserted for that environment.

If you want to automatically insert a label for a environment but with
an empty prefix, use the empty string @code{""} as the cdr of the
corresponding entry.
@end defopt

As a default selection, @AUCTeX{} will suggest the environment last
inserted or, as the first choice the value of the variable
@code{LaTeX-default-environment}.

@defopt LaTeX-default-environment
Default environment to insert when invoking @code{LaTeX-environment}
first time.  When the current environment is @samp{document}, it is
overriden by @code{LaTeX-default-document-environment}.
@end defopt

@defvar LaTeX-default-document-environment
Default environment when invoking @samp{LaTeX-environment} and the
current environment is @samp{document}.  It is intended to be used in
@LaTeX{} class style files.  For example, in @file{beamer.el} it is set
to @code{frame}, in @file{letter.el} to @code{letter}, and in
@file{slides.el} to @code{slide}.
@end defvar

If the document is empty, or the cursor is placed at the top of the
document, @AUCTeX{} will default to insert a @samp{document} environment
prompting also for the insertion of @samp{\documentclass} and
@samp{\usepackage} macros.  You will be prompted for a new package until
you enter nothing.  If you do not want to insert any @samp{\usepackage}
at all, just press @key{RET} at the first @samp{Packages} prompt.

@AUCTeX{} distinguishes normal and expert environments.  By default, it
will offer completion only for normal environments.  This behavior is
controlled by the user option @code{TeX-complete-expert-commands}.

@defopt TeX-complete-expert-commands
Complete macros and environments marked as expert commands.

Possible values are nil, t, or a list of style names.

@table @asis
@item nil
Don't complete expert commands (default).
@item t
Always complete expert commands.
@item (@var{styles} @dots{})
Only complete expert commands of @var{styles}.
@end table
@end defopt


@menu
* Equations::                   Equations
* Floats::                      Floats
* Itemize-like::                Itemize-like Environments
* Tabular-like::                Tabular-like Environments
* Customizing Environments::    Customizing Environments
@end menu

You can close the current environment with @kbd{C-c ]}, but we suggest
that you use @kbd{C-c C-e} to insert complete environments instead.

@deffn Command LaTeX-close-environment
@kindex C-c ]
(@kbd{C-c ]}) Insert an @samp{\end} that matches the current environment.
@end deffn

@AUCTeX{} offers keyboard shortcuts for moving point to the beginning
and to the end of the current environment.
@deffn Command LaTeX-find-matching-begin
@kindex C-M-a
(@kbd{C-M-a}) Move point to the @samp{\begin} of the current
environment.

If this command is called inside a comment and
@code{LaTeX-syntactic-comments} is enabled, try to find the environment
in commented regions with the same comment prefix.
@end deffn

@deffn Command LaTeX-find-matching-end
@kindex C-M-e
(@kbd{C-M-e}) Move point to the @samp{\end} of the current environment.

If this command is called inside a comment and
@code{LaTeX-syntactic-comments} is enabled, try to find the environment
in commented regions with the same comment prefix.
@end deffn

@node Equations
@subsection Equations
@cindex Equations
@cindex Equation
@cindex Eqnarray
@cindex amsmath

When inserting equation-like environments, the @samp{\label} will have a
default prefix, which is controlled by the following variables:

@defopt LaTeX-equation-label
Prefix to use for `equation' labels.
@end defopt

@defopt LaTeX-eqnarray-label
Prefix to use for `eqnarray' labels.
@end defopt

@defopt LaTeX-amsmath-label
Prefix to use for amsmath equation labels.  Amsmath equations include
@samp{align}, @samp{alignat}, @samp{xalignat}, @samp{multline},
@samp{flalign} and @samp{gather}.
@end defopt

@node Floats
@subsection Floats
@cindex Floats
@cindex Figures
@cindex Figure environment
@cindex Tables
@cindex Table environment

Figures and tables (i.e., floats) may also be inserted using @AUCTeX{}.
After choosing either `figure' or `table' in the environment list
described above, you will be prompted for a number of additional things.

@table @var
@item float position
This is the optional argument of float environments that controls how
they are placed in the final document.  In @LaTeX{} this is a sequence
of the letters @samp{htbp} as described in the @LaTeX{} manual.  The
value will default to the value of @code{LaTeX-float}.
@vindex LaTeX-float

@item caption
This is the caption of the float.  The default is to insert the caption
at the bottom of the float.  You can specify floats where the caption
should be placed at the top with @code{LaTeX-top-caption-list}.
@vindex LaTeX-top-caption-list

@item short caption
If the specified caption is greater than a specific length, then a short
caption is prompted for and it is inserted as an optional argument to
the @samp{\caption} macro.  The length that a caption needs to be before
prompting for a short version is controlled by
@code{LaTeX-short-caption-prompt-length}.
@vindex LaTeX-short-caption-prompt-length

@item label
The label of this float.  The label will have a default prefix, which is
controlled by the variables @code{LaTeX-figure-label} and
@code{LaTeX-table-label}.
@vindex LaTeX-figure-label
@vindex LaTeX-table-label
@cindex Prefix for labels
@cindex Label prefix
@cindex Labels
@end table

Moreover, you will be asked if you want the contents of the float
environment to be horizontally centered.  Upon a positive answer a
@samp{\centering} macro will be inserted at the beginning of the float
environment.

@defopt LaTeX-float
Default placement for floats.
@end defopt

@defopt LaTeX-figure-label
Prefix to use for figure labels.
@end defopt

@defopt LaTeX-table-label
Prefix to use for table labels.
@end defopt

@defopt LaTeX-top-caption-list
List of float environments with top caption.
@end defopt

@defopt LaTeX-short-caption-prompt-length
Number of chars a caption should be before prompting for a short
caption.
@end defopt

@node Itemize-like
@subsection Itemize-like Environments
@cindex Itemize
@cindex Enumerates
@cindex Descriptions
@cindex Items
@cindex \item

In an itemize-like environment, nodes (i.e., @samp{\item}s) may be
inserted using @kbd{C-c @key{LFD}}.

@deffn Command LaTeX-insert-item
@kindex C-c @key{LFD}
(@kbd{C-c @key{LFD}}) Close the current item, move to the next line and
insert an appropriate @samp{\item} for the current environment.  That is,
`itemize' and `enumerate' will have @samp{\item } inserted, while
`description' will have @samp{\item[] } inserted.
@end deffn

@defopt TeX-arg-item-label-p
If non-nil, you will always be asked for optional label in items.
Otherwise, you will be asked only in description environments.
@end defopt

@node Tabular-like
@subsection Tabular-like Environments
@cindex amsmath

When inserting Tabular-like environments, that is, `tabular' `array'
etc., you will be prompted for a template for that environment.
Related variables:

@defopt LaTeX-default-format
Default format string for array and tabular environments.
@end defopt

@defopt LaTeX-default-width
Default width for minipage and tabular* environments.
@end defopt

@defopt LaTeX-default-position
Default position string for array and tabular environments.  If nil,
act like the empty string is given, but don't prompt for a position.
@end defopt

@AUCTeX{} calculates the number of columns from the format string and
inserts the suitable number of ampersands.

You can use @kbd{C-c @key{LFD}} (@code{LaTeX-insert-item}) to terminate
rows in these environments.  It supplies line break macro @samp{\\} and
inserts the suitable number of ampersands on the next line.  @AUCTeX{}
also supports the @samp{*@{num@}@{cols@}} notation (which may contain
another @samp{*}-expression) in the format string when calculating the
number of ampersands.  Please note that @samp{num} and @samp{cols} must
be enclosed in braces; expressions like @samp{*2l} are not recognized
correctly by the algorithm.

@deffn Command LaTeX-insert-item
@kindex C-c @key{LFD}
(@kbd{C-c @key{LFD}}) Close the current row with @samp{\\}, move to the
next line and insert an appropriate number of ampersands for the current
environment.
@end deffn

Similar supports are provided for various amsmath environments such as
@samp{align}, @samp{gather}, @samp{alignat}, @samp{matrix} etc.  Try
typing @kbd{C-c @key{LFD}} in these environments.  It recognizes the
current environment and does the appropriate job depending on the
context.

@node Customizing Environments
@subsection Customizing Environments

@xref{Adding Environments}, for how to customize the list of known
environments.

@node Mathematics
@section Entering Mathematics
@cindex Mathematics
@cindex Symbols
@cindex Abbreviations
@vindex LaTeX-math-default

@TeX{} is written by a mathematician, and has always contained good
support for formatting mathematical text.  @AUCTeX{} supports this
tradition, by offering a special minor mode for entering text with many
mathematical symbols.  You can enter this mode by typing @kbd{C-c
~}.

@deffn Command LaTeX-math-mode
@kindex C-c ~
(@kbd{C-c ~}) Toggle @LaTeX{} Math mode.  This is a minor mode rebinding
the key @code{LaTeX-math-abbrev-prefix} to allow easy typing of
mathematical symbols.  @kbd{`} will read a character from the keyboard,
and insert the symbol as specified in @code{LaTeX-math-default} and
@code{LaTeX-math-list}.  If given a prefix argument, the symbol will be
surrounded by dollar signs.
@end deffn

You can use another prefix key (instead of @kbd{`}) by  setting the
variable @code{LaTeX-math-abbrev-prefix}.

To enable @LaTeX{} Math mode by default, add the following in your
init file such as @file{init.el} or @file{.emacs}:
@lisp
(add-hook 'LaTeX-mode-hook #'LaTeX-math-mode)
@end lisp

@defopt LaTeX-math-abbrev-prefix
A string containing the prefix of @code{LaTeX-math-mode} commands; This
value defaults to @kbd{`}.

The string has to be a key or key sequence in a format understood by the
@code{kbd} macro.  This corresponds to the syntax usually used in the
manuals for Emacs Lisp.
@end defopt

The variable @code{LaTeX-math-list} allows you to add your own mappings.

@defopt LaTeX-math-list
A list containing user-defined keys and commands to be used in @LaTeX{}
Math mode.  Each entry should be a list of two to four elements.

First, the key to be used after @code{LaTeX-math-abbrev-prefix} for
macro insertion.  If it is nil, the symbol has no associated
keystroke (it is available in the menu, though).

Second, a string representing the name of the macro (without a leading
backslash.)

Third, a string representing the name of a submenu the command should be
added to.  Use a list of strings in case of nested menus.

Fourth, the position of a Unicode character to be displayed in the menu
alongside the macro name.  This is an integer value.
@end defopt

@defopt LaTeX-math-menu-unicode
Whether the @LaTeX{} Math menu should try using Unicode for effect.  Your Emacs
built must be able to display include Unicode characters in menus for
this feature.
@end defopt

@AUCTeX{}'s reference card @file{tex-ref.tex} includes a list of all
math mode commands.

@cindex subscript
@cindex superscript
@kindex _
@kindex ^
@AUCTeX{} can help you write subscripts and superscripts in math
constructs by automatically inserting a pair of braces after typing
@key{_} or @key{^} respectively and putting point between the braces.
In order to enable this feature, set the variable
@code{TeX-electric-sub-and-superscript} to a non-nil value.

@defopt TeX-electric-sub-and-superscript
If non-nil, insert braces after typing @key{^} and @key{_} in math mode.
@end defopt

@cindex input method
You can automatically turn off input methods, used to input non-ascii
characters, when you begin to enter math constructs.

@defopt TeX-math-input-method-off-regexp
Input method matching this regular expression is turned off when @kbd{$}
is typed to begin math mode or a math environment is inserted by
@kbd{C-c C-e} (@code{LaTeX-environment}).
@end defopt

@node Completion
@section Completion
@cindex Completion
@cindex Expansion
@cindex Macro expansion
@cindex Macro completion
@cindex Macro arguments
@cindex Arguments to @TeX{} macros

Emacs lisp programmers probably know the @code{lisp-complete-symbol}
command which was bound to @kbd{M-@key{TAB}} until completion-at-point
became the new standard completion facility (see below).  Users of the
wonderful ispell mode know and love the @code{ispell-complete-word}
command from that package.  Similarly, @AUCTeX{} has a
@code{TeX-complete-symbol} command, by default bound to
@kbd{M-@key{TAB}} which is equivalent to @kbd{C-M-i}.  Using
@code{TeX-complete-symbol} makes it easier to type and remember the
names of long @LaTeX{} macros.

In order to use @code{TeX-complete-symbol}, you should write a backslash
and the start of the macro.  Typing @kbd{M-@key{TAB}} will now complete
as much of the macro, as it unambiguously can.  For example, if you type
`@samp{\renewc}' and then @kbd{M-@key{TAB}}, it will expand to
`@samp{\renewcommand}'.  But there's more: if point is just after
@samp{\begin@{}, then @code{TeX-complete-symbol} will complete @LaTeX{}
environments, etc.  This is controlled by @code{TeX-complete-list}.

@deffn Command TeX-complete-symbol
@kindex M-@key{TAB}
(@kbd{M-@key{TAB}})  Complete @TeX{} symbol before point.
@end deffn

@defvar TeX-complete-list
List of ways to complete the preceding text.

Each entry is a list with the following elements:

@enumerate
@item
Regexp matching the preceding text or a predicate of arity 0 which
returns non-nil and sets `match-data' appropriately if it is applicable.
@item
A number indicating the subgroup in the regexp containing the text.
@item
A function returning an alist of possible completions.
@item
Text to append after a succesful completion.
@end enumerate

Or alternatively:

@enumerate
@item
Regexp matching the preceding text.
@item
Function to do the actual completion.
@end enumerate
@end defvar

More recent Emacs versions have a new completion mechanism.  Modes may
define and register custom @code{completion-at-point} functions and when the
user invokes @code{completion-at-point} (usually bound to
@kbd{M-@key{TAB}}), all such registered functions are consulted for
checking for possible completions.  Modern completion UIs like
@i{company-mode} support this completion-at-point facility.

@defun TeX--completion-at-point
@AUCTeX{}'s completion-at-point function which is automatically added to
@code{completion-at-point-functions} in @TeX{} and @LaTeX{} buffers.

It offers the same completion candidates as would
@code{TeX-complete-symbol} (and is also controlled by
@code{TeX-complete-list}) except that it doesn't fall back on
@code{ispell-complete-word} which would be awkward with completion UIs
like @i{company-mode}.
@end defun

A more direct way to insert a macro is with @code{TeX-insert-macro},
bound to @kbd{C-c C-m} which is equivalent to @kbd{C-c @key{RET}}.  It
has the advantage over completion that it knows about the argument of
most standard @LaTeX{} macros, and will prompt for them.  It also knows
about the type of the arguments, so it will for example give completion
for the argument to @samp{\include}.  Some examples are listed below.

@deffn Command TeX-insert-macro
@kindex C-c C-m
(@kbd{C-c C-m} or @kbd{C-c @key{RET}}) Prompt (with completion) for the
name of a @TeX{} macro, and if @AUCTeX{} knows the macro, prompt for
each argument.
@end deffn

As a default selection, @AUCTeX{} will suggest the macro last inserted
or, as the first choice the value of the variable
@code{TeX-default-macro}.

@defopt TeX-default-macro
Default macro to insert when invoking @code{TeX-insert-macro} first time.
@end defopt

@defopt TeX-insert-macro-default-style
Specifies whether @code{TeX-insert-macro} will ask for all optional
arguments.

If set to the symbol @code{show-optional-args}, @code{TeX-insert-macro}
asks for optional arguments of @TeX{} marcos, unless the previous
optional argument has been rejected.  If set to
@code{show-all-optional-args}, @code{TeX-insert-macro} asks for all
optional arguments.  @code{mandatory-args-only}, @code{TeX-insert-macro}
asks only for mandatory arguments.  When @code{TeX-insert-macro} is
called with prefix argument (@kbd{C-u}), it's the other way round.
@c FIXME: Now that the option has 3 candidates, it isn't clear what "the
@c other way round" means.

Note that for some macros, there are special mechanisms, e.g.@:
@code{LaTeX-includegraphics-options-alist} and
@code{TeX-arg-cite-note-p}.
@end defopt


A faster alternative is to enable the option
@code{TeX-electric-escape}.

@defopt TeX-electric-escape
If this is non-nil, typing the @TeX{} escape character @kbd{\} will
invoke the command @code{TeX-electric-macro}.

In Texinfo mode, the command is invoked by @kbd{@@} instead.
@end defopt

The difference between @code{TeX-insert-macro} and
@code{TeX-electric-macro} is that space key @key{SPC} will complete and exit from the
minibuffer in @code{TeX-electric-macro}.  Use @key{TAB} if you merely
want to complete.

@deffn Command TeX-electric-macro
Prompt (with completion) for the name of a @TeX{} macro,
and if @AUCTeX{} knows the macro, prompt for each argument.
Space (@key{SPC}) will complete and exit.
@end deffn

By default @AUCTeX{} will put an empty set braces @samp{@{@}} after a
macro with no arguments to stop it from eating the next whitespace.
This is suppressed inside math mode and can be disabled totally by
setting @code{TeX-insert-braces} to nil.

@defopt TeX-insert-braces
If non-nil, append a empty pair of braces after inserting a macro with
no arguments.
@end defopt

@defopt TeX-insert-braces-alist
Control the insertion of a pair of braces after a macro on a per macro
basis.

This variable is an alist.  Each element is a cons cell, whose car is
the macro name, and the cdr is non-nil or nil, depending on whether a
pair of braces should be, respectively, appended or not to the macro.

If a macro has an element in this variable, @AUCTeX{} will
use its value to decide what to do, whatever the value of the variable
@code{TeX-insert-braces}.
@end defopt

Completions work because @AUCTeX{} can analyze @TeX{} files, and store
symbols in Emacs Lisp files for later retrieval.  @xref{Automatic}, for
more information.

@AUCTeX{} distinguishes normal and expert macros.  By default, it will
offer completion only for normal commands.  This behavior can be
controlled using the user option @code{TeX-complete-expert-commands}.

@defopt TeX-complete-expert-commands
Complete macros and environments marked as expert commands.

Possible values are nil, t, or a list of style names.

@table @asis
@item nil
Don't complete expert commands (default).
@item t
Always complete expert commands.
@item (@var{styles} @dots{})
Only complete expert commands of @var{styles}.
@end table
@end defopt


@cindex \cite, completion of
@cindex Bib@TeX{}, completion
@cindex cite, completion of
@cindex bibliography, completion
@cindex citations, completion of
@cindex \label, completion
@cindex \ref, completion
@cindex labels, completion of
@AUCTeX{} will also make completion for many macro arguments, for
example existing labels when you enter a @samp{\ref} macro with
@code{TeX-insert-macro} or @code{TeX-electric-macro}, and Bib@TeX{}
entries when you enter a @samp{\cite} macro.  For this kind of
completion to work, parsing must be enabled as described in
@ref{Parsing Files}.  For @samp{\cite} you must also make sure that
the Bib@TeX{} files have been saved at least once after you enabled
automatic parsing on save, and that the basename of the Bib@TeX{} file
does not conflict with the basename of one of @TeX{} files.

@node Marking
@section Marking Environments, Sections, or Texinfo Nodes

You can mark the current environment by typing @kbd{C-c .}, or the
current section by typing @kbd{C-c *}.

In Texinfo documents you can type @kbd{C-M-h} to mark the current node.

When the region is set, the point is moved to its beginning and the mark
to its end.

@menu
* Marking (LaTeX):: @LaTeX{} Commands for Marking Environments and Sections
* Marking (Texinfo):: Texinfo Commands for Marking Environments, Sections, and Nodes
@end menu

@node Marking (LaTeX)
@subsection @LaTeX{} Commands for Marking Environments and Sections

@deffn Command LaTeX-mark-section
@kindex C-c *
(@kbd{C-c *}) Set mark at end of current logical section, and point at
top.

With a non-nil prefix argument, mark only the region from the current
section start to the next sectioning command.  Thereby subsections are
not being marked.  Otherwise, any included subsections are also marked
along with current section.
@end deffn

@deffn Command LaTeX-mark-environment
@kindex C-c .
(@kbd{C-c .}) Set mark to the end of the current environment and point
to the matching beginning.

If a prefix argument is given, mark the respective number of enclosing
environments.  The command will not work properly if there are
unbalanced begin-end pairs in comments and verbatim environments.
@end deffn

@node Marking (Texinfo)
@subsection Texinfo Commands for Marking Environments and Sections

@deffn Command Texinfo-mark-section
@kindex C-c *
(@kbd{C-c *}) Mark the current section, with inclusion of any containing
node.

@vindex outline-regexp
@vindex texinfo-section-list
The current section is detected as starting by any of the structuring
commands matched by the regular expression in the variable
@code{outline-regexp} which in turn is a regular expression matching any
element of the variable @code{texinfo-section-list}.

With a non-nil prefix argument, mark only the region from the current
section start to the next sectioning command.  Thereby subsections are
not being marked.  Otherwise, any included subsections are also marked.

Note that when the current section is starting immediately after a node
command, then the node command is also marked as part of the section.
@end deffn

@deffn Command Texinfo-mark-environment
@kindex C-c .
(@kbd{C-c .}) Set mark to the end of the current environment and point
to the matching beginning.

If a prefix argument is given, mark the respective number of enclosing
environments.  The command will not work properly if there are
unbalanced begin-end pairs in comments and verbatim environments.
@end deffn

@deffn Command Texinfo-mark-node
@kindex C-M-h
(@kbd{C-M-h}) Mark the current node.  This is the node in which point is
located.  It is starting at the previous occurrence of the keyword
@code{@@node} and ending at next occurrence of the keywords
@code{@@node} or @code{@@bye}.
@end deffn

@node Commenting
@section Commenting

It is often necessary to comment out temporarily a region of @TeX{} or
@LaTeX{} code.  This can be done with the commands @kbd{C-c ;} and
@kbd{C-c %}.  @kbd{C-c ;} will comment out all lines in the current
region, while @kbd{C-c %} will comment out the current paragraph.
Type @kbd{C-c ;} again to uncomment all lines of a commented region,
or @kbd{C-c %} again to uncomment all comment lines around point.
These commands will insert or remove a single @samp{%} respectively.

@deffn Command TeX-comment-or-uncomment-region
@kindex C-c ;
(@kbd{C-c ;}) Add or remove @samp{%} from the beginning of each line
in the current region.  Uncommenting works only if the region encloses
solely commented lines.  If @AUCTeX{} should not try to guess if the
region should be commented or uncommented the commands
@code{TeX-comment-region} and @code{TeX-uncomment-region} can be used
to explicitly comment or uncomment the region in concern.
@end deffn

@deffn Command TeX-comment-or-uncomment-paragraph
@kindex C-c %
(@kbd{C-c %}) Add or remove @samp{%} from the beginning of each line
in the current paragraph.  When removing @samp{%} characters the
paragraph is considered to consist of all preceding and succeeding
lines starting with a @samp{%}, until the first non-comment line.
@end deffn

@node Indenting
@section Indenting
@cindex Formatting
@cindex Indenting
@cindex Indentation
@cindex Reformatting
@cindex Reindenting

Indentation means the addition of whitespace at the beginning of lines
to reflect special syntactical constructs.  This makes it easier to see
the structure of the document, and to catch errors such as a missing
closing brace.  Thus, the indentation is done for precisely the same
reasons that you would indent ordinary computer programs.

Indentation is done by @LaTeX{} environments and by @TeX{} groups, that
is the body of an environment is indented by the value of
@code{LaTeX-indent-level} (default 2).  Also, items of an `itemize-like'
environment are indented by the value of @code{LaTeX-item-indent},
default @minus{}2.  (Items are identified with the help of
@code{LaTeX-item-regexp}.)  If more environments are nested, they are
indented `accumulated' just like most programming languages usually are
seen indented in nested constructs.
@vindex LaTeX-indent-level
@vindex LaTeX-item-indent
@vindex LaTeX-item-regexp

You can explicitely indent single lines, usually by pressing @key{TAB},
or marked regions by calling @code{indent-region} on it.  If you have
@code{auto-fill-mode} enabled and a line is broken while you type it,
Emacs automatically cares about the indentation in the following line.
If you want to have a similar behavior upon typing @key{RET}, you can
customize the variable @code{TeX-newline-function} and change the
default of @code{newline} which does no indentation to
@code{newline-and-indent} which indents the new line or
@code{reindent-then-newline-and-indent} which indents both the current
and the new line.
@vindex TeX-newline-function
@findex indent-region
@cindex auto-fill-mode

There are certain @LaTeX{} environments which should be indented in a
special way, like @samp{tabular} or @samp{verbatim}.  Those environments
may be specified in the variable @code{LaTeX-indent-environment-list}
together with their special indentation functions.  Taking the
@samp{verbatim} environment as an example you can see that
@code{current-indentation} is used as the indentation function.  This
will stop @AUCTeX{} from doing any indentation in the environment if you
hit @key{TAB} for example.
@vindex LaTeX-indent-environment-list

There are environments in @code{LaTeX-indent-environment-list} which do
not bring a special indentation function with them.  This is due to the
fact that first the respective functions are not implemented yet and
second that filling will be disabled for the specified environments.
This shall prevent the source code from being messed up by accidently
filling those environments with the standard filling routine.  If you
think that providing special filling routines for such environments
would be an appropriate and challenging task for you, you are invited to
contribute.  (@xref{Filling}, for further information about the filling
functionality.)
@vindex LaTeX-indent-environment-list

The check for the indentation function may be enabled or disabled by
customizing the variable @code{LaTeX-indent-environment-check}.
@vindex LaTeX-indent-environment-check

@cindex align.el
@findex align-current
As a side note with regard to formatting special environments: Newer
Emacsen include @file{align.el} and therefore provide some support for
formatting @samp{tabular} and @samp{tabbing} environments with the
function @code{align-current} which will nicely align columns in the
source code.

@AUCTeX{} is able to format commented parts of your code just as any
other part.  This means @LaTeX{} environments and @TeX{} groups in
comments will be indented syntactically correct if the variable
@code{LaTeX-syntactic-comments} is set to t.  If you disable it,
comments will be filled like normal text and no syntactic indentation
will be done.
@vindex LaTeX-syntactic-comments

Following you will find a list of most commands and variables related
to indenting with a small summary in each case:

@table @kbd
@item @key{TAB}
@kindex @key{TAB}
@findex LaTeX-indent-line
@code{LaTeX-indent-line} will indent the current line.

@item @key{LFD}
@itemx C-j
@kindex @key{LFD}
@kindex C-j
@code{newline-and-indent} inserts a new line (much like @key{RET}) and
moves the cursor to an appropriate position by the left margin.

Most keyboards nowadays lack a linefeed key and @kbd{C-j} may be tedious
to type.  Therefore you can customize @AUCTeX{} to perform indentation
upon typing @key{RET} as well.  The respective option is called
@code{TeX-newline-function}.
@end table

@defopt LaTeX-indent-environment-list
List of environments with special indentation.  The second element in
each entry is the function to calculate the indentation level in
columns.

@c FIXME: The situation has changed, hasn't it?
The filling code currently cannot handle tabular-like environments
which will be completely messed-up if you try to format them.  This is
why most of these environments are included in this customization
option without a special indentation function.  This will prevent that
they get filled.
@end defopt

@defopt LaTeX-indent-level
Number of spaces to add to the indentation for each @samp{\begin} not
matched by a @samp{\end}.
@end defopt

@defopt LaTeX-item-indent
Number of spaces to add to the indentation for @samp{\item}'s in list
environments.
@end defopt

@defopt TeX-brace-indent-level
Number of spaces to add to the indentation for each @samp{@{} not
matched by a @samp{@}}.
@end defopt

@defopt LaTeX-syntactic-comments
If non-nil comments will be filled and indented according to @LaTeX{}
syntax.  Otherwise they will be filled like normal text.
@end defopt

@defopt TeX-newline-function
Used to specify the function which is called when @key{RET} is pressed.
This will normally be @code{newline} which simply inserts a new line.
In case you want to have @AUCTeX{} do indentation as well when you press
@key{RET}, use the built-in functions @code{newline-and-indent} or
@code{reindent-then-newline-and-indent}.  The former inserts a new line
and indents the following line, i.e.@: it moves the cursor to the right
position and therefore acts as if you pressed @key{LFD}.  The latter
function additionally indents the current line.  If you choose
@samp{Other}, you can specify your own fancy function to be called when
@key{RET} is pressed.
@end defopt

@vindex LaTeX-begin-regexp
@vindex LaTeX-end-regexp
@AUCTeX{} treats by default @samp{\[...\]} math mode as a regular
environment and indents it accordingly.  If you do not like such
behavior you only need to remove @code{\|\[} and @code{\|\]} from
@code{LaTeX-begin-regexp} and @code{LaTeX-end-regexp} variables
respectively.

@node Filling
@section Filling
@cindex Filling
@cindex Formatting
@cindex Reformatting
@cindex Refilling
@findex auto-fill-mode
@findex turn-on-auto-fill
@vindex fill-column

Filling deals with the insertion of line breaks to prevent lines from
becoming wider than what is specified in @code{fill-column}.  The
linebreaks will be inserted automatically if @code{auto-fill-mode} is
enabled.  In this case the source is not only filled but also indented
automatically as you write it.

@code{auto-fill-mode} can be enabled for @AUCTeX{} by calling
@code{turn-on-auto-fill} in one of the hooks @AUCTeX{} is running.
@xref{Modes and Hooks}.  As an example, if you want to enable
@code{auto-fill-mode} in @code{LaTeX-mode}, put the following into your
init file:

@lisp
(add-hook 'LaTeX-mode-hook #'turn-on-auto-fill)
@end lisp

You can manually fill explicitely marked regions, paragraphs,
environments, complete sections, or the whole buffer.  (Note that manual
filling in @AUCTeX{} will indent the start of the region to be filled in
contrast to many other Emacs modes.)

There are some syntactical constructs which are handled specially with
regard to filling.  These are so-called @dfn{code comments} and
@dfn{paragraph commands}.

Code comments are comments preceded by code or text in the same line.
Upon filling a region, code comments themselves will not get filled.
Filling is done from the start of the region to the line with the code
comment and continues after it.  In order to prevent overfull lines in
the source code, a linebreak will be inserted before the last
non-comment word by default.  This can be changed by customizing
@code{LaTeX-fill-break-before-code-comments}.  If you have overfull
lines with code comments you can fill those explicitely by calling
@code{LaTeX-fill-paragraph} or pressing @kbd{M-q} with the cursor
positioned on them.  This will add linebreaks in the comment and indent
subsequent comment lines to the column of the comment in the first line
of the code comment.  In this special case @kbd{M-q} only acts on the
current line and not on the whole paragraph.

Lines with @samp{\par} are treated similarly to code comments,
i.e.@: @samp{\par} will be treated as paragraph boundary which should not
be followed by other code or text.  But it is not treated as a real
paragraph boundary like an empty line where filling a paragraph would
stop.

Paragraph commands like @samp{\section} or @samp{\noindent} (the list of
commands is defined by @code{LaTeX-paragraph-commands}) are often to be
placed in their own line(s).  This means they should not be consecuted
with any preceding or following adjacent lines of text.  @AUCTeX{} will
prevent this from happening if you do not put any text except another
macro after the end of the last brace of the respective macro.  If
there is other text after the macro, @AUCTeX{} regards this as a sign
that the macro is part of the following paragraph.
@vindex LaTeX-paragraph-commands

Here are some examples:

@example
\begin@{quote@}
  text text text text
@end example

@example
\begin@{quote@}\label@{foo@}
  text text text text
@end example

If you press @kbd{M-q} on the first line in both examples, nothing will
change.  But if you write

@example
\begin@{quote@} text
  text text text text
@end example
@noindent
and press @kbd{M-q}, you will get

@example
\begin@{quote@} text text text text text
@end example

Besides code comments and paragraph commands, another speciality of
filling in @AUCTeX{} involves commented lines.  You should be aware that
these comments are treated as islands in the rest of the @LaTeX{} code
if syntactic filling is enabled.  This means, for example, if you try to
fill an environment with @code{LaTeX-fill-environment} and have the
cursor placed on a commented line which does not have a surrounding
environment inside the comment, @AUCTeX{} will report an error.
@findex LaTeX-fill-environment

The relevant commands and variables with regard to filling are:

@table @kbd
@item C-c C-q C-p
@kindex C-c C-q C-p
@findex LaTeX-fill-paragraph
@code{LaTeX-fill-paragraph} will fill and indent the current paragraph.

@item M-q
@kindex M-q
Alias for @kbd{C-c C-q C-p}

@item C-c C-q C-e
@kindex C-c C-q C-e
@findex LaTeX-fill-environment
@code{LaTeX-fill-environment} will fill and indent the current
environment.  This may e.g.@: be the `document' environment, in which case
the entire document will be formatted.

@item C-c C-q C-s
@kindex C-c C-q C-s
@findex LaTeX-fill-section
@code{LaTeX-fill-section} will fill and indent the current logical
sectional unit.

@item C-c C-q C-r
@kindex C-c C-q C-r
@findex LaTeX-fill-region
@code{LaTeX-fill-region} will fill and indent the current region.
@end table

@defopt LaTeX-fill-break-at-separators
List of separators before or after which respectively linebreaks will
be inserted if they do not fit into one line.  The separators can be
curly braces, brackets, switches for inline math (@samp{$}, @samp{\(},
@samp{\)}) and switches for display math (@samp{\[}, @samp{\]}).  Such
formatting can be useful to make macros and math more visible or to
prevent overfull lines in the @LaTeX{} source in case a package for
displaying formatted @TeX{} output inside the Emacs buffer, like
preview-latex, is used.
@end defopt

@defopt LaTeX-fill-break-before-code-comments
Code comments are comments preceded by some other text in the same line.
When a paragraph containing such a comment is to be filled, the comment
start will be seen as a border after which no line breaks will be
inserted in the same line.  If the option
@code{LaTeX-fill-break-before-code-comments} is enabled (which is the
default) and the comment does not fit into the line, a line break will
be inserted before the last non-comment word to minimize the chance that
the line becomes overfull.
@end defopt

@defopt LaTeX-fill-excluded-macros
A list of macro names (without leading backslash) for whose arguments
filling should be disabled.  Typically, you will want to add macros here
which have long, multi-line arguments.  An example is
@code{\pgfplotstabletypeset} from the pgfplotstable package which is
used as shown in the following listing:

@verbatim
\pgfplotstabletypeset[skip first n=4]{%
  XYZ Format,
  Version 1.234
  Date 2010-09-01
  @author Mustermann
  A B C
  1 2 3
  4 5 6
}
@end verbatim
@end defopt

@node Display
@chapter Controlling Screen Display

It is often desirable to get visual help of what markup code in a text
actually does without having to decipher it explicitly.  For this
purpose Emacs and @AUCTeX{} provide font locking (also known as syntax
highlighting) which visually sets off markup code like macros or
environments by using different colors or fonts.  For example text to be
typeset in italics can be displayed with an italic font in the editor as
well, or labels and references get their own distinct color.

While font locking helps you grasp the purpose of markup code and
separate markup from content, the markup code can still be distracting.
@AUCTeX{} lets you hide those parts and show them again at request with
its built-in support for hiding macros and environments which we call
folding here.

Besides folding of macros and environments, @AUCTeX{} provides support
for Emacs' outline mode which lets you narrow the buffer content to
certain sections of your text by hiding the parts not belonging to these
sections.

Moreover, you can focus in a specific portion of the code by narrowing
the buffer to the desired region.  @AUCTeX{} provides also functions to
narrow the buffer to the current group and to @LaTeX{} environments.

@AUCTeX{} also provides some WYSIWYG features.

First, you can customize @code{font-latex-fontify-script} to enable
special formatting of @code{^} superscripts and @code{_} subscripts
(@pxref{Font Locking}).

Secondly, @AUCTeX{} with GNU Emacs 25 or later can display certain math
macros using Unicode characters, e.g., @code{\alpha} as α.  This is
called prettification and is lightweight and reasonable robust
(@pxref{Prettifying}).

A more accurate approach is provided by @previewlatex{}, a subsystem of
@AUCTeX{}, see @ref{Top,,Introduction,preview-latex,The @previewlatex{}
Manual}.  This system uses @LaTeX{} to generate images that are then
displayed in your buffer.  It is extremely accurate but can be fragile
with some packages (like older pgf versions).

Please note that you can use prettification and @previewlatex{} together.

@menu
* Font Locking::                Font Locking
* Folding::                     Folding Macros and Environments
* Outline::                     Outlining the Document
* Narrowing::                   Restricting display and editing to a portion of the buffer
* Prettifying::                 Displaying Greek and math macros as Unicode characters
@end menu

@node Font Locking
@section Font Locking
@cindex Font Locking
@cindex Syntax Highlighting
@cindex font-latex

Font locking is supposed to improve readability of the source code by
highlighting certain keywords with different colors or fonts.  It
thereby lets you recognize the function of markup code to a certain
extent without having to read the markup command.  For general
information on controlling font locking with Emacs' Font Lock mode, see
@ref{Font Lock, , Font Lock Mode, emacs, GNU Emacs Manual}.

@defopt TeX-install-font-lock
Once font locking is enabled globally or for the major modes provided by
@AUCTeX{}, the font locking patterns and functionality of @fontlatex{}
are activated by default.  You can switch to a different font locking
scheme or disable font locking in @AUCTeX{} by customizing the variable
@code{TeX-install-font-lock}.

Besides @fontlatex{} @AUCTeX{} ships with a scheme which is derived
from Emacs' default @LaTeX{} mode and activated by choosing
@code{tex-font-setup}.  Be aware that this scheme is not coupled with
@AUCTeX{}'s style system and not the focus of development.  Therefore
and due to @fontlatex{} being much more feature-rich the following
explanations will only cover @fontlatex{}.

In case you want to hook in your own fontification scheme, you can
choose @code{other} and insert the name of the function which sets up
your font locking patterns.  If you want to disable fontification in
@AUCTeX{} completely, choose @code{ignore}.
@end defopt

@fontlatex{} provides many options for customization which are
accessible with @kbd{M-x customize-group @key{RET} font-latex @key{RET}}.  For this
description the various options are explained in conceptional groups.

@menu
* Fontification of macros::     Fontification of macros
* Fontification of quotes::     Fontification of quotes
* Fontification of math::       Fontification of math constructs
* Verbatim content::            Verbatim macros and environments
* Faces::                       Faces used by font-latex
* Known problems::              Known fontification problems
@end menu

@node Fontification of macros
@subsection Fontification of macros

Highlighting of macros can be customized by adapting keyword lists which
can be found in the customization group @code{font-latex-keywords}.

Three types of macros can be handled differently with respect to
fontification:

@enumerate
@item
Commands of the form @samp{\foo[bar]@{baz@}} which consist of the macro
itself, optional arguments in square brackets and mandatory arguments in
curly braces.  For the command itself the face
@code{font-lock-keyword-face} will be used and for the optional
arguments the face @code{font-lock-variable-name-face}.  The face
applied to the mandatory argument depends on the macro class represented
by the respective built-in variables.
@item
Declaration macros of the form @samp{@{\foo text@}} which consist of the
macro which may be enclosed in a @TeX{} group together with text to be
affected by the macro.  In case a @TeX{} group is present, the macro
will get the face @code{font-lock-keyword-face} and the text will get
the face configured for the respective macro class.  If no @TeX{} group
is present, the latter face will be applied to the macro itself.
@item
Simple macros of the form @samp{\foo} which do not have any arguments or
groupings.  The respective face will be applied to the macro itself.
@end enumerate

Customization variables for @samp{\foo[bar]@{baz@}} type macros allow
both the macro name and the sequence of arguments to be specified.  The
latter is done with a string which can contain the characters
@table @samp
@item *
indicating the existence of a starred variant for the macro,
@item [
for optional arguments in brackets,
@item @{
for mandatory arguments in braces,
@item \
for mandatory arguments consisting of a single macro and
@item |
as a prefix indicating that two alternatives are following.
@end table
For example the specifier for @samp{\documentclass} would be @samp{[@{}
because the macro has one optional followed by one mandatory argument.
The specifier for @samp{\newcommand} would be @samp{*|@{\[[@{} because
there is a starred variant, the mandatory argument following the macro
name can be a macro or a @TeX{} group which can be followed by two
optional arguments and the last token is a mandatory argument in braces.

Customization variables for the @samp{@{\foo text@}} and @samp{\foo}
types are simple lists of strings where each entry is a macro name
(without the leading backslash).

@subheading General macro classes

@fontlatex{} provides keyword lists for different macro classes which
are described in the following table:

@vindex font-latex-match-function-keywords
@vindex font-latex-match-reference-keywords
@vindex font-latex-match-textual-keywords
@vindex font-latex-match-variable-keywords
@vindex font-latex-match-warning-keywords
@table @code
@item font-latex-match-function-keywords
Keywords for macros defining or related to functions, like
@samp{\newcommand}.@*
Type: @samp{\macro[...]@{...@}}@*
Face: @code{font-lock-function-name-face}

@item font-latex-match-reference-keywords
Keywords for macros defining or related to references, like
@samp{\ref}.@*
Type: @samp{\macro[...]@{...@}}@*
Face: @code{font-lock-constant-face}

@item font-latex-match-textual-keywords
Keywords for macros specifying textual content, like @samp{\caption}.@*
Type: @samp{\macro[...]@{...@}}@*
Face: @code{font-lock-type-face}

@item font-latex-match-variable-keywords
Keywords for macros defining or related to variables, like
@samp{\setlength}.@*
Type: @samp{\macro[...]@{...@}}@*
Face: @code{font-lock-variable-name-face}

@item font-latex-match-warning-keywords
Keywords for important macros, e.g.@: affecting line or page break, like
@samp{\clearpage}.@*
Type: @samp{\macro}@*
Face: @code{font-latex-warning-face}
@end table

@subheading Sectioning commands
@cindex Sectioning commands, fontification of

Sectioning commands are macros like @samp{\chapter} or @samp{\section}.
For these commands there are two fontification schemes which may be
selected by customizing the variable @code{font-latex-fontify-sectioning}.

@defopt font-latex-fontify-sectioning
@c FIXME: Is @vindex correct?
@vindex font-latex-sectioning-0-face
@vindex font-latex-sectioning-1-face
@vindex font-latex-sectioning-2-face
@vindex font-latex-sectioning-3-face
@vindex font-latex-sectioning-4-face
@vindex font-latex-sectioning-5-face
Per default sectioning commands will be shown in a larger, proportional
font, which corresponds to a number for this variable.  The font size
varies with the sectioning level, e.g.@: @samp{\part}
(@code{font-latex-sectioning-0-face}) has a larger font than
@samp{\paragraph} (@code{font-latex-sectioning-5-face}).  Typically,
values from 1.05 to 1.3 for @code{font-latex-fontify-sectioning} give
best results, depending on your font setup.  If you rather like to use
the base font and a different color, set the variable to the symbol
@samp{color}.  In this case the face @code{font-lock-type-face} will be
used to fontify the argument of the sectioning commands.
@end defopt

@vindex font-latex-match-sectioning-0-keywords
@vindex font-latex-match-sectioning-1-keywords
@vindex font-latex-match-sectioning-2-keywords
@vindex font-latex-match-sectioning-3-keywords
@vindex font-latex-match-sectioning-4-keywords
@vindex font-latex-match-sectioning-5-keywords
You can make @fontlatex{} aware of your own sectioning commands be
adding them to the keyword lists:
@code{font-latex-match-sectioning-0-keywords}
(@code{font-latex-sectioning-0-face}) @dots{}
@code{font-latex-match-sectioning-5-keywords}
(@code{font-latex-sectioning-5-face}).

@vindex font-latex-slide-title-face
@vindex font-latex-match-slide-title-keywords
Related to sectioning there is special support for slide titles which
may be fontified with the face @code{font-latex-slide-title-face}.  You
can add macros which should appear in this face by customizing the
variable @code{font-latex-match-slide-title-keywords}.

@subheading Commands for changing fonts

@LaTeX{} provides various macros for changing fonts or font attributes.
For example, you can select an italic font with @samp{\textit@{...@}} or
bold with @samp{\textbf@{...@}}.  An alternative way to specify these
fonts is to use special macros in @TeX{} groups, like @samp{@{\itshape
...@}} for italics and @samp{@{\bfseries ...@}} for bold.  As mentioned
above, we call the former variants commands and the latter
declarations.

Besides the macros for changing fonts provided by @LaTeX{} there is an
infinite number of other macros---either defined by yourself for logical
markup or defined by macro packages---which affect the font in the
typeset text.  While @LaTeX{}'s built-in macros and macros of packages
known by @AUCTeX{} are already handled by @fontlatex{}, different
keyword lists per type style and macro type are provided for entering
your own macros which are listed in the table below.

@vindex font-latex-match-bold-command-keywords
@vindex font-latex-match-italic-command-keywords
@vindex font-latex-match-math-command-keywords
@vindex font-latex-match-type-command-keywords
@vindex font-latex-match-bold-declaration-keywords
@vindex font-latex-match-italic-declaration-keywords
@vindex font-latex-match-type-declaration-keywords
@table @code
@item font-latex-match-bold-command-keywords
Keywords for commands specifying a bold type style.@*
Face: @code{font-latex-bold-face}
@item font-latex-match-italic-command-keywords
Keywords for commands specifying an italic font.@*
Face: @code{font-latex-italic-face}
@item font-latex-match-math-command-keywords
Keywords for commands specifying a math font.@*
Face: @code{font-latex-math-face}
@item font-latex-match-type-command-keywords
Keywords for commands specifying a typewriter font.@*
Face: @code{font-lock-type-face}
@item font-latex-match-bold-declaration-keywords
Keywords for declarations specifying a bold type style.@*
Face: @code{font-latex-bold-face}
@item font-latex-match-italic-declaration-keywords
Keywords for declarations specifying an italic font.@*
Face: @code{font-latex-italic-face}
@item font-latex-match-type-declaration-keywords
Keywords for declarations specifying a typewriter font.@*
Face: @code{font-latex-type-face}
@end table

@subheading Deactivating defaults of built-in keyword classes

@vindex font-latex-deactivated-keyword-classes
@fontlatex{} ships with predefined lists of keywords for the classes
described above.  You can disable these defaults per class by
customizing the variable @code{font-latex-deactivated-keyword-classes}.
This is a list of strings for keyword classes to be deactivated.  Valid
entries are "warning", "variable", "biblatexnoarg", "biblatex",
"reference", "function" , "sectioning-0", "sectioning-1",
"sectioning-2", "sectioning-3", "sectioning-4", "sectioning-5",
"slide-title", "textual", "bold-command", "italic-command",
"math-command", "type-command", "bold-declaration",
"italic-declaration", "type-declaration".

You can also get rid of certain keywords only.  For example if you want
to remove highlighting of footnotes as references you can put the
following stanza into your init file:

@lisp
(eval-after-load "font-latex"
  '(setq-default
    font-latex-match-reference-keywords-local
    (remove (assoc-string "footnote"
            font-latex-match-reference-keywords-local)
                font-latex-match-reference-keywords-local)))
@end lisp

But note that this means fiddling with @fontlatex{}'s internals and is
not guaranteed to work in future versions of @fontlatex{}.

@subheading User-defined keyword classes

In case the customization options explained above do not suffice for
your needs, you can specify your own keyword classes by customizing the
variable @code{font-latex-user-keyword-classes}.

@defopt font-latex-user-keyword-classes
Every keyword class consists of four parts, a name, a list of keywords,
a face and a specifier for the type of macros to be highlighted.

When adding new entries, you have to use unique values for the class
names, i.e.@: they must not clash with names of the built-in keyword
classes or other names given by you.  Additionally the names must not
contain spaces.

The list of keywords defines which commands and declarations should be
covered by the keyword class.  A keyword can either be a simple command
name omitting the leading backslash or a list consisting of the command
name and a string specifying the sequence of arguments for the command.

The face argument can either be an existing face or face attributes
made by you.

There are three alternatives for the type of keywords---``Command with
arguments'', ``Declaration inside @TeX{} group'' and ``Command without
arguments''---which correspond with the macro types explained above.
@end defopt

@node Fontification of quotes
@subsection Fontification of quotes
@cindex Quotes, fontification of

Text in quotation marks is displayed with the face
@code{font-latex-string-face}.  Besides the various forms of opening and
closing double and single quotation marks, so-called guillemets (<<, >>)
can be used for quoting.  Because there are two styles of using
them---French style: << text >>; German style: >>text<<---you can
customize the variable @code{font-latex-quotes} to tell @fontlatex{}
which type you are using if the correct value cannot be derived from
document properties.

@defopt font-latex-quotes
The default value of @code{font-latex-quotes} is @samp{auto} which means
that @fontlatex{} will try to derive the correct type of quotation mark
matching from document properties like the language option supplied to
the babel @LaTeX{} package.

If the automatic detection fails for you and you mostly use one specific
style you can set it to a specific language-dependent value as well.
Set the value to @samp{german} if you are using >>German quotes<< and to
@samp{french} if you are using << French quotes >>.  @fontlatex{} will
recognize the different ways these quotes can be given in your source
code, i.e.@: (@samp{"<}, @samp{">}), (@samp{<<}, @samp{>>}) and the
respective 8-bit variants.

If you set @code{font-latex-quotes} to nil, quoted content will not be
fontified.
@end defopt


@node Fontification of math
@subsection Fontification of mathematical constructs
@cindex Math, fontification of
@cindex Subscript, fontification of
@cindex Superscript, fontification of

@vindex font-latex-match-math-command-keywords
@vindex font-latex-math-environments
@vindex texmathp-tex-commands
@vindex texmathp-tex-commands-default
In @LaTeX{} mathematics can be indicated by a variety of different
methods: toggles (like dollar signs), macros and environments.  Math
constructs known by @fontlatex{} are displayed with the face
@code{font-latex-math-face}.  Support for dollar signs and shorthands
like @samp{\(...\)} or @samp{\[...\]} is built-in and not customizable.
Support for other math macros and environments can be adapted by
customizing the variables @code{font-latex-match-math-command-keywords}
and @code{texmathp-tex-commands} respectively.  It is no longer
recommended to customize @code{font-latex-math-environments}.

To convert your customization in @code{font-latex-math-environments}
into @code{texmathp-tex-commands}, please register your own math
environments, together with starred variants if any, as entries of
@code{env-on} type in @code{texmathp-tex-commands}, then clear out
@code{font-latex-math-environments}.  You have to restart Emacs for this
new customization to take effect for fontification.

In order to make math constructs more readable, @fontlatex{} displays
subscript and superscript parts in a smaller font and raised or lowered
respectively.  This fontification feature can be controlled with the
variables @code{font-latex-fontify-script} and
@code{font-latex-script-display}.

@defopt font-latex-fontify-script
If non-nil, fontify subscript and superscript strings.  Concretely, this
means that the scripts are raised or lowered.

Another possiblity is setting this variable to the symbol
@code{multi-level}.  In this case, in a formula @i{x^@{y^z@}}, @i{y} is
raised above and smaller than @i{x}, and @i{z} is raised above and
smaller than @i{y}.  With many script levels, the text might become too
small to be readable.  (See @code{font-latex-fontify-script-max-level}
below.)

Lastly, you can set this variable to @code{invisible} whose behavior is
like @code{multi-level}, and in addition the super-/subscript characters
@i{^} and @i{_} are not displayed.
@end defopt

@vindex font-latex-superscript-face
@vindex font-latex-subscript-face
@defopt font-latex-fontify-script-max-level
Maximum scriptification level for which script faces are applied.

The faces @code{font-latex-superscript-face} and
@code{font-latex-subscript-face} define custom @code{:height} values <
1.0.  Therefore, scripts are displayed with a slightly smaller font than
normal math text.  If @code{font-latex-fontify-script} is
@code{multi-level} or @code{invisible}, the font size becomes too small
to be readable after a few levels.  This option allows to specify the
maximum level after which the size of the script text won’t be shrunken
anymore.

For example, in the expression @i{x^@{y^@{z^a_b@}@}}, @i{x} has
scriptification level 0, @i{y} has level 1, @i{z} has level 2, and both
@i{a} and @i{b} have scriptification level 3.

If @code{font-latex-fontify-script-max-level} was 2, then @i{z}, @i{a},
and @i{b} would have the same font size.  If it was 3 or more, then
@i{a} and @i{b} were smaller than @i{z} just in the same way as @i{z} is
smaller than @i{y} and @i{y} is smaller than @i{x}.
@end defopt

@vindex font-latex-script-char-face
The script characters @samp{^} and @samp{_} themselves are also
fontified with an own face named @code{font-latex-script-char-face}.

@defopt font-latex-script-display
Display specification for subscript and superscript content.  The car is
used for subscript, the cdr is used for superscript.  The feature is
implemented using so-called display properties.  For information on what
exactly to specify for the values, see @ref{Other Display Specs, , Other
Display Specifications, elisp, GNU Emacs Lisp Reference Manual}.
@end defopt

@node Verbatim content
@subsection Verbatim macros and environments
@cindex Verbatim, fontification of

Usually it is not desirable to have content to be typeset verbatim
highlighted according to @LaTeX{} syntax.  Therefore this content will
be fontified uniformly with the face @code{font-latex-verbatim-face}.

@vindex LaTeX-verbatim-macros-with-delims
@vindex LaTeX-verbatim-macros-with-braces
@vindex LaTeX-verbatim-environments
@fontlatex{} differentiates three different types of verbatim
constructs for fontification.  Macros with special characters like | as
delimiters, macros with braces, and environments.  Which macros and
environments are recognized is controlled by the variables
@code{LaTeX-verbatim-macros-with-delims},
@code{LaTeX-verbatim-macros-with-braces}, and
@code{LaTeX-verbatim-environments} respectively.

@node Faces
@subsection Faces used by @fontlatex{}
@cindex Faces

In case you want to change the colors and fonts used by @fontlatex{}
please refer to the faces mentioned in the explanations above and use
@kbd{M-x customize-face @key{RET} <face> @key{RET}}.  All faces defined by
@fontlatex{} are accessible through a customization group by typing
@kbd{M-x customize-group @key{RET} font-latex-highlighting-faces @key{RET}}.

@node Known problems
@subsection Known fontification problems
@cindex Dollar signs, color bleed with
@cindex Math, fontification problems with

In certain cases the fontification machinery fails to interpret buffer
contents correctly.  This can lead to color bleed, i.e.@: large parts of a
buffer get fontified with an inappropriate face.  A typical situation
for this to happen is the use of a dollar sign (@samp{$}) in a verbatim
macro or environment.  If @fontlatex{} is not aware of the verbatim
construct, it assumes the dollar sign to be a toggle for mathematics and
fontifies the following buffer content with the respective face until it
finds a closing dollar sign or till the end of the buffer.

As a remedy you can make the verbatim construct known to @fontlatex{}
(@pxref{Verbatim content}).  If this is not possible, you can insert a
commented dollar sign (@samp{%$}) at the next suitable end of line as a
quick workaround.  In docTeX documents, @samp{^^A$} is also available
for similar purpose.

@node Folding
@section Folding Macros and Environments
@cindex Outlining
@cindex Folding
@cindex Reveal
@cindex Auto-Reveal
@cindex Hide Macros

A popular complaint about markup languages like @TeX{} and @LaTeX{} is
that there is too much clutter in the source text and that one cannot
focus well on the content.  There are macros where you are only
interested in the content they are enclosing, like font specifiers where
the content might already be fontified in a special way by font locking.
Or macros the content of which you only want to see when actually
editing it, like footnotes or citations.  Similarly you might find
certain environments or comments distracting when trying to concentrate
on the body of your document.

With @AUCTeX{}'s folding functionality you can collapse those items and
replace them by a fixed string, the content of one of their arguments,
or a mixture of both.  If you want to make the original text visible
again in order to view or edit it, move point sideways onto the
placeholder (also called display string) or left-click with the mouse
pointer on it.  The
macro or environment will unfold automatically, stay open as long as
point is inside of it and collapse again once you move point out of it.
(Note that folding of environments currently does not work in every
@AUCTeX{} mode.)

In order to use this feature, you have to activate @code{TeX-fold-mode}
which will activate the auto-reveal feature and the necessary commands
to hide and show macros and environments.  You can activate the mode in
a certain buffer by typing the command @kbd{M-x TeX-fold-mode @key{RET}} or
using the keyboard shortcut @kbd{C-c C-o C-f}.  If you want to use it
every time you edit a @LaTeX{} document, add it to a hook:
@findex TeX-fold-mode
@kindex C-c C-o C-f

@lisp
(add-hook 'LaTeX-mode-hook (lambda ()
                             (TeX-fold-mode 1)))
@end lisp

If it should be activated in all @AUCTeX{} modes, use
@code{TeX-mode-hook} instead of @code{LaTeX-mode-hook}.

Once the mode is active there are several commands available to hide
and show macros, environments and comments:

@deffn Command TeX-fold-buffer
@kindex C-c C-o C-b
(@kbd{C-c C-o C-b}) Hide all foldable items in the current buffer
according to the setting of @code{TeX-fold-type-list}.

If you want to have this done automatically every time you open a file,
add it to a hook and make sure the function is called after font locking
is set up for the buffer.  The following code should accomplish this:

@lisp
(add-hook 'find-file-hook #'TeX-fold-buffer t)
@end lisp

The command can be used any time to refresh the whole buffer and fold
any new macros and environments which were inserted after the last
invocation of the command.
@end deffn

@defopt TeX-fold-type-list
List of symbols determining the item classes to consider for folding.
This can be macros, environments and comments.  Per default only macros
and environments are folded.
@end defopt

@defopt TeX-fold-force-fontify
In order for all folded content to get the right faces, the whole buffer
has to be fontified before folding is carried out.
@code{TeX-fold-buffer} therefore will force fontification of unfontified
regions.  As this will prolong the time folding takes, you can prevent
forced fontification by customizing the variable
@code{TeX-fold-force-fontify}.
@end defopt

@defopt TeX-fold-auto
By default, a macro inserted with @code{TeX-insert-macro} (@kbd{C-c
C-m}) will not be folded.  Set this variable to a non-nil value to
aumatically fold macros as soon as they are inserted.
@end defopt

@defopt TeX-fold-preserve-comments
By default items found in comments will be folded.  If your comments
often contain unfinished code this might lead to problems.  Give this
variable a non-nil value and foldable items in your comments will be
left alone.
@end defopt

@defopt TeX-fold-unfold-around-mark
When this variable is non-nil and there is an active regione, text
around the mark will be kept unfolded.
@end defopt

@deffn Command TeX-fold-region
@kindex C-c C-o C-r
(@kbd{C-c C-o C-r}) Hide all configured macros in the marked region.
@end deffn

@deffn Command TeX-fold-paragraph
@kindex C-c C-o C-p
(@kbd{C-c C-o C-p}) Hide all configured macros in the paragraph
containing point.
@end deffn

@deffn Command TeX-fold-macro
@kindex C-c C-o C-m
(@kbd{C-c C-o C-m}) Hide the macro on which point currently is located.
If the name of the macro is found in @code{TeX-fold-macro-spec-list},
the respective display string will be shown instead.  If it is not
found, the name of the macro in sqare brackets or the default string for
unspecified macros (@code{TeX-fold-unspec-macro-display-string}) will be
shown, depending on the value of the variable
@code{TeX-fold-unspec-use-name}.
@end deffn

@deffn Command TeX-fold-env
@kindex C-c C-o C-e
(@kbd{C-c C-o C-e}) Hide the environment on which point currently is
located.  The behavior regarding the display string is analogous to
@code{TeX-fold-macro} and determined by the variables
@code{TeX-fold-env-spec-list} and
@code{TeX-fold-unspec-env-display-string} respectively.
@end deffn

@deffn Command TeX-fold-math
Hide the math macro on which point currently is located.  If the name of
the macro is found in @code{TeX-fold-math-spec-list}, the respective
display string will be shown instead.  If it is not found, the name of
the macro in sqare brackets or the default string for unspecified macros
(@code{TeX-fold-unspec-macro-display-string}) will be shown, depending
on the value of the variable @code{TeX-fold-unspec-use-name}.
@end deffn

@deffn Command TeX-fold-comment
@kindex C-c C-o C-c
(@kbd{C-c C-o C-c}) Hide the comment point is located on.
@end deffn

@deffn Command TeX-fold-clearout-buffer
@kindex C-c C-o b
(@kbd{C-c C-o b}) Permanently unfold all macros and environments in the
current buffer.
@end deffn

@deffn Command TeX-fold-clearout-region
@kindex C-c C-o r
(@kbd{C-c C-o r}) Permanently unfold all macros and environments in the
marked region.
@end deffn

@deffn Command TeX-fold-clearout-paragraph
@kindex C-c C-o p
(@kbd{C-c C-o p}) Permanently unfold all macros and environments in the
paragraph containing point.
@end deffn

@deffn Command TeX-fold-clearout-item
@kindex C-c C-o i
(@kbd{C-c C-o i}) Permanently show the macro or environment on which
point currently is located.  In contrast to temporarily opening the
macro when point is moved sideways onto it, the macro will be
permanently unfolded and will not collapse again once point is leaving
it.
@end deffn

@deffn Command TeX-fold-dwim
@kindex C-c C-o C-o
(@kbd{C-c C-o C-o}) Hide or show items according to the current context.
If there is folded content, unfold it.  If there is a marked region,
fold all configured content in this region.  If there is no folded
content but a macro or environment, fold it.
@end deffn

@vindex TeX-fold-command-prefix
In case you want to use a different prefix than @kbd{C-c C-o} for these
commands you can customize the variable @code{TeX-fold-command-prefix}.
(Note that this will not change the key binding for activating the
mode.)

The commands above will only take macros or environments into
consideration which are specified in the variables
@code{TeX-fold-macro-spec-list} or @code{TeX-fold-env-spec-list}
respectively.

@defopt TeX-fold-macro-spec-list
List of replacement specifiers and macros to fold.  The specifier can be
a string, an integer or a function symbol.

If you specify a string, it will be used as a display replacement for
the whole macro.  Numbers in braces, brackets, parens or angle brackets
will be replaced by the respective macro argument.  For example
@samp{@{1@}} will be replaced by the first mandatory argument of the
macro.  One can also define alternatives within the specifier which are
used if an argument is not found.  Alternatives are separated by
@samp{||}.  They are most useful with optional arguments.  As an
example, the default specifier for @samp{\item} is @samp{[1]:||*} which
means that if there is an optional argument, its value is shown followed
by a colon.  If there is no optional argument, only an asterisk is used
as the display string.

If you specify a number as the first element, the content of the
respective mandatory argument of a @LaTeX{} macro will be used as the
placeholder.

If the first element is a function symbol, the function will be called
with all mandatory arguments of the macro and the result of the function
call will be used as a replacement for the macro.

The placeholder is made by copying the text from the buffer together with
its properties, i.e.@: its face as well.  If fontification has not
happened when this is done (e.g.@: because of lazy font locking) the
intended fontification will not show up.  As a workaround you can leave
Emacs idle a few seconds and wait for stealth font locking to finish
before you fold the buffer.  Or you just re-fold the buffer with
@code{TeX-fold-buffer} when you notice a wrong fontification.
@end defopt

@defopt TeX-fold-env-spec-list
List of display strings or argument numbers and environments to fold.
Argument numbers refer to the @samp{\begin} statement.  That means if
you have e.g.@: @samp{\begin@{tabularx@}@{\linewidth@}@{XXX@} ...
\end@{tabularx@}} and specify 3 as the argument number, the resulting
display string will be ``XXX''.
@end defopt

@defopt TeX-fold-math-spec-list
List of display strings and math macros to fold.
@end defopt

@vindex LaTeX-fold-macro-spec-list
@vindex LaTeX-fold-env-spec-list
@vindex LaTeX-fold-math-spec-list
The variables @code{TeX-fold-macro-spec-list},
@code{TeX-fold-env-spec-list}, and @code{TeX-fold-math-spec-list} apply
to any @AUCTeX{} mode.  If you want to make settings which are only
applied to @LaTeX{} mode, you can use the mode-specific variables
@code{LaTeX-fold-macro-spec-list}, @code{LaTeX-fold-env-spec-list}, and
@code{LaTeX-fold-math-spec-list}

@defopt TeX-fold-unspec-macro-display-string
Default display string for macros which are not specified in
@code{TeX-fold-macro-spec-list}.
@end defopt

@defopt TeX-fold-unspec-env-display-string
Default display string for environments which are not specified in
@code{TeX-fold-env-spec-list}.
@end defopt

@defopt TeX-fold-unspec-use-name
If non-nil the name of the macro or environment surrounded by square
brackets is used as display string, otherwise the defaults specified in
@code{TeX-fold-unspec-macro-display-string} or
@code{TeX-fold-unspec-env-display-string} respectively.
@end defopt

When you hover with the mouse pointer over folded content, its original
text will be shown in a tooltip or the echo area depending on Tooltip
mode being activate.  In order to avoid exorbitantly big tooltips and to
cater for the limited space in the echo area the content will be cropped
after a certain amount of characters defined by the variable
@code{TeX-fold-help-echo-max-length}.

@defopt TeX-fold-help-echo-max-length
Maximum length of original text displayed in a tooltip or the echo area
for folded content.  Set it to zero in order to disable this feature.
@end defopt


@node Outline
@section Outlining the Document
@cindex Outlining
@cindex Headers
@cindex Sections
@cindex Overview
@cindex Folding

@AUCTeX{} supports the standard outline minor mode using
@LaTeX{}/@ConTeXt{} sectioning commands as header lines.  @xref{Outline
Mode, , Outline Mode, emacs, GNU Emacs Manual}.

You can add your own headings by setting the variable
@code{TeX-outline-extra}.

@defvar TeX-outline-extra
List of extra @TeX{} outline levels.

Each element is a list with two entries.  The first entry is the regular
expression matching a header, and the second is the level of the header.
A @samp{^} is automatically prepended to the regular expressions in the
list, so they must match text at the beginning of the line.

See @code{LaTeX-section-list} or @code{ConTeXt-INTERFACE-section-list}
for existing header levels.
@end defvar

The following example add @samp{\item} and @samp{\bibliography} headers,
with @samp{\bibliography} at the same outline level as @samp{\section},
and @samp{\item} being below @samp{\subparagraph}.

@lisp
(setq TeX-outline-extra
      '(("[ \t]*\\\\\\(bib\\)?item\\b" 7)
        ("\\\\bibliography\\b" 2)))
@end lisp

@c FIXME: Isn't this much outdated?
You may want to check out the unbundled @file{out-xtra} package for even
better outline support.  It is available from your favorite emacs lisp
archive.

@node Narrowing
@section Narrowing

Sometimes you want to focus your attention to a limited region of the
code.  You can do that by restricting the text addressable by editing
commands and hiding the rest of the buffer with the narrowing functions,
@pxref{Narrowing,,,emacs,GNU Emacs Manual}.  In addition, @AUCTeX{}
provides a couple of other commands to narrow the buffer to a group,
i.e.@: a region enclosed in a pair of curly braces, and to @LaTeX{}
environments.

@deffn Command TeX-narrow-to-group
@kindex C-x n g
(@kbd{C-x n g}) Make text outside current group invisible.
@end deffn

@deffn Command LaTeX-narrow-to-environment @var{count}
@kindex C-x n e
(@kbd{C-x n e}) Make text outside current environment invisible.  With
optional argument @var{count} keep visible that number of enclosing
environmens.
@end deffn

Like other standard narrowing functions, the above commands are
disabled.  Attempting to use them asks for confirmation and gives you
the option of enabling them; if you enable the commands, confirmation
will no longer be required for them.

@node Prettifying
@section Prettifying

Emacs 25 is able to prettify symbols in programming language buffers,
@pxref{Misc for Programs,,,emacs,GNU Emacs Manual}.  The canonical
example is to display @code{(lambda () ...)} as @code{(λ () ...)} in
Lisp buffers.

@AUCTeX{} can use this feature in order to display certain math macros
and greek letters using their Unicode representation, too.  For example,
the @TeX{} code @code{\alpha \times \beta} will be displayed as @code{α
× β}.  When point is on one of the characters, it'll be unprettified
automatically, meaning you see the verbatim text again.  For this
behaviour however you need to set
@code{prettify-symbols-unprettify-at-point} to t or @code{right-edge}
which will unprettify the symbol when point moves into or near it.

To enable prettification in @AUCTeX{}, simply add
@code{prettify-symbols-mode} to @code{TeX-mode-hook}.  If you enabled
prettification globally with @code{global-prettify-symbols-mode}, then
it's automatically enabled in @AUCTeX{}, too.

You can also add custom symbol unicode-character pairs for
prettification by adding to @code{tex--prettify-symbols-alist}.  Note
that this variable is part of Emacs' stock @code{tex-mode.el} and used
by that and @AUCTeX{}.

@node Processing
@chapter Starting Processors, Viewers and Other Programs

The most powerful features of @AUCTeX{} may be those allowing you to run
@TeX{}, @LaTeX{}, @ConTeXt{} and other external commands like Bib@TeX{}
and @command{makeindex} from within Emacs, viewing and printing the
results, and moreover allowing you to @emph{debug} your documents.

@cindex tool bar, toolbar
@vindex LaTeX-enable-toolbar
@vindex plain-TeX-enable-toolbar
@vindex TeX-bar-TeX-buttons
@vindex TeX-bar-TeX-all-button-alists
@vindex TeX-bar-LaTeX-buttons
@vindex TeX-bar-LaTeX-button-alist
@AUCTeX{} comes with a special tool bar for @TeX{} and @LaTeX{} which
provides buttons for the most important commands.  You can enable or
disable it by customizing the options @code{plain-TeX-enable-toolbar}
and @code{LaTeX-enable-toolbar} in the @code{TeX-tool-bar} customization
group.  You can also customize the buttons by the options
@code{TeX-bar-TeX-buttons}, @code{TeX-bar-TeX-all-button-alists},
@code{TeX-bar-LaTeX-buttons} and @code{TeX-bar-LaTeX-button-alist}.
@c FIXME: Write details about customizing tool bar.

@menu
* Commands::                    Invoking external commands.
* Viewing::                     Invoking external viewers.
* Debugging::                   Debugging @TeX{} and @LaTeX{} output.
* Checking::                    Checking the document.
* Control::                     Controlling the processes.
* Cleaning::                    Cleaning intermediate and output files.
* Documentation::               Documentation about macros and packages.
@end menu

@node Commands
@section Executing Commands
@cindex Formatting
@cindex Running @LaTeX{}
@cindex Running @TeX{}
@cindex @LaTeX{}
@cindex @TeX{}
@cindex Running commands
@cindex Default command
@cindex Header
@cindex Trailer
@cindex Setting the header
@cindex Setting the trailer
@cindex Region
@cindex Region file
@cindex Setting the default command
@cindex Commands
@cindex External Commands
@cindex Indexing
@cindex Making an index
@cindex Running @command{makeindex}
@cindex @command{makeindex}
@cindex Bib@TeX{}
@cindex Bibliography
@cindex Literature
@cindex Running Bib@TeX{}
@cindex Making a bibliography
@cindex Printing
@cindex Writing to a printer

Formatting the document with @TeX{}, @LaTeX{} or @ConTeXt{}, viewing
with a previewer, printing the document, running Bib@TeX{}, making an
index, or checking the document with @command{lacheck} or
@command{chktex} all require running an external command.

@menu
* Starting a Command::          Starting a Command on a Document or Region
* Selecting a Command::         Selecting and Executing a Command
* Processor Options::           Options for @TeX{} Processors
@end menu

@node Starting a Command
@subsection Starting a Command on a Document or Region

There are two ways to run an external command, you can either run it on
the current document with @code{TeX-command-master}, or on the current
region with @code{TeX-command-region}.  A special case of running @TeX{}
on a region is @code{TeX-command-buffer} which differs from
@code{TeX-command-master} if the current buffer is not its own master
file.

@deffn Command TeX-command-master
@kindex C-c C-c
(@kbd{C-c C-c})  Query the user for a command, and run it on the master
file associated with the current buffer.  The name of the master file is
controlled by the variable @code{TeX-master}.  The available commands are
controlled by the variable @code{TeX-command-list}.
@vindex TeX-master
@vindex TeX-command-list
@end deffn

@deffn Command TeX-command-region
@kindex C-c C-r
(@kbd{C-c C-r}) Query the user for a command, and run it on the contents
of the selected region.  The region contents are written into the region
file, after extracting the header and trailer from the master file.  If
mark is inactive (which can happen with Transient Mark mode), use the
old region.  See also the command @code{TeX-pin-region} about how to fix
a region.

The name of the region file is controlled by the variable
@code{TeX-region}.  The name of the master file is controlled by the
variable @code{TeX-master}.  The header is all text up to the line
matching the regular expression @code{TeX-header-end}.  The trailer is
all text from the line matching the regular expression
@code{TeX-trailer-start}.  The available commands are controlled by the
variable @code{TeX-command-list}.
@vindex TeX-region
@vindex TeX-header-end
@vindex TeX-trailer-start
@vindex TeX-master
@vindex TeX-command-list
@end deffn

@deffn Command TeX-command-buffer
@kindex C-c C-b
(@kbd{C-c C-b}) Query the user for a command, and apply it to the
contents of the current buffer.  The buffer contents are written into
the region file, after extracting the header and trailer from the master
file.  The command is then actually run on the region file.  See above
for details.
@end deffn

@deffn Command LaTeX-command-section
@kindex C-c C-z
(@kbd{C-c C-z}) Query the user for a command, and apply it to the
current section (or part, chapter, subsection, paragraph, or
subparagraph).  What makes the current section is determined by
@code{LaTeX-command-section-level} which can be enlarged/shrunken using
@code{LaTeX-command-section-change-level} (@kbd{C-c M-z}).  The given
numeric prefix arg is added to the current value of
@code{LaTeX-command-section-level}.  By default,
@code{LaTeX-command-section-level} is initialized with the current
document's @code{LaTeX-largest-level}.  The buffer contents are written
into the region file, after extracting the header and trailer from the
master file.  The command is then actually run on the region file.  See
@code{TeX-command-region} for details.
@end deffn

It is also possible to compile automatically the whole document until it
is ready with a single command: @code{TeX-command-run-all}.

@deffn Command TeX-command-run-all
@kindex C-c C-a
(@kbd{C-c C-a}) Compile the current document until an error occurs or it
is finished.  If compilation finishes successfully, run the viewer at
the end.
@end deffn

Here are some relevant variables.

@defopt TeX-region
The name of the file for temporarily storing the text when formatting
the current region.
@end defopt

@defopt TeX-header-end
A regular expression matching the end of the header.  By default, this
is @samp{\begin@{document@}} in @LaTeX{} mode and @samp{%**end of
header} in plain @TeX{} mode.
@end defopt

@defopt TeX-trailer-start
A regular expression matching the start of the trailer.  By default,
this is @samp{\end@{document@}} in @LaTeX{} mode and @samp{\bye} in
plain @TeX{} mode.
@end defopt

If you want to change the values of @code{TeX-header-end} and
@code{TeX-trailer-start} you can do this for all files by setting the
variables in a mode hook or per file by specifying them as file
variables (@pxref{File Variables,,,emacs,The Emacs Editor}).

@deffn Command TeX-pin-region
@kindex C-c C-t C-r
(@kbd{C-c C-t C-r}) If you don't have a mode like Transient Mark mode
active, where marks get disabled automatically, the region would need to
get properly set before each call to @code{TeX-command-region}.  If you
fix the current region with @kbd{C-c C-t C-r}, then it will get used for
more commands even though mark and point may change.  An explicitly
activated mark, however, will always define a new region when calling
@code{TeX-command-region}.
@end deffn

@c FIXME: The former half of this paragraph is incorrect.
@c - `TeX-(La)TeX-sentinel' depends on `TeX-active-*', which act
@c   according to the value of `TeX-current-process-region-p'.
@c - Both C-c C-c and C-c C-r overwrite `TeX-current-process-region-p'.
@c Therefore, if the user types C-c C-r before the process invoked by
@c C-c C-c finishes, the sentinel for the latter process doesn't work
@c as expected.
@AUCTeX{} will allow one process for each document, plus one process
for the region file to be active at the same time.  Thus, if you are
editing @var{n} different documents, you can have @var{n} plus one
processes running at the same time.  If the last process you started was
on the region, the commands described in @ref{Debugging} and
@ref{Control} will work on that process, otherwise they will work on the
process associated with the current document.

@node Selecting a Command
@subsection Selecting and Executing a Command

Once you started the command selection with @kbd{C-c C-c}, @kbd{C-c C-r}
or @kbd{C-c C-b} you will be prompted for the type of command.
@AUCTeX{} will try to guess which command is appropriate in the given
situation and propose it as default.  Usually this is a processor like
@samp{TeX} or @samp{LaTeX} if the document was changed or a viewer if
the document was just typeset.  Other commands can be selected in the
minibuffer with completion support by typing @key{TAB}.

@vindex TeX-command-list
@vindex TeX-expand-list
The available commands are defined by the variable
@code{TeX-command-list}.  Per default it includes commands for
typesetting the document (e.g.@: @samp{LaTeX}), for viewing the output
(@samp{View}), for printing (@samp{Print}), for generating an index
(@samp{Index}) or for spell checking (@samp{Spell}) to name but a few.
You can also add your own commands by adding entries to
@code{TeX-command-list}.  Refer to its doc string for information about
its syntax.  You might also want to look at @code{TeX-expand-list} to
learn about the expanders you can use in @code{TeX-command-list}.

Note that the default of the variable occasionally changes.  Therefore
it is advisable to add to the list rather than overwriting it.  You can
do this with a call to @code{add-to-list} in your init file.  For
example, if you wanted to add a command for running a program called
@samp{foo} on the master or region file, you could do this with the
following form.

@lisp
(eval-after-load "tex"
  '(add-to-list 'TeX-command-list
                '("Foo" "foo %s" TeX-run-command t t :help "Run foo") t))
@end lisp

As mentioned before, @AUCTeX{} will try to guess what command you want
to invoke.  If you want to use another command than @samp{TeX},
@samp{LaTeX} or whatever processor @AUCTeX{} thinks is appropriate for
the current mode, set the variable @code{TeX-command-default}.  You can
do this for all files by setting it in a mode hook or per file by
specifying it as a file variable (@pxref{File Variables,,,emacs,The
Emacs Editor}).

@defopt TeX-command-default
The default command to run in this buffer.  Must be an entry in
@code{TeX-command-list}.
@end defopt

@cindex Biber
@cindex biblatex
In case you use biblatex in a document, when automatic parsing is
enabled @AUCTeX{} checks the value of @samp{backend} option given to
biblatex at load time to decide whether to use Bib@TeX{} or Biber for
bibliography processing.  Should @AUCTeX{} fail to detect the right
backend, you can use the file local @code{LaTeX-biblatex-use-Biber}
variable.
@defvr Variable LaTeX-biblatex-use-Biber
If this boolean variable is set as file local, it tells to @AUCTeX{}
whether to use Biber with biblatex.  In this case, the autodetection of
the biblatex backend will be overridden.  You may want to set locally
this variable if automatic parsing is not enabled.
@end defvr

After confirming a command to execute, @AUCTeX{} will try to save any
buffers related to the document, and check if the document needs to be
reformatted.  If the variable @code{TeX-save-query} is non-nil,
@AUCTeX{} will query before saving each file.  By default @AUCTeX{} will
check emacs buffers associated with files in the current directory, in
one of the @code{TeX-macro-private} directories, and in the
@code{TeX-macro-global} directories.  You can change this by setting the
variable @code{TeX-check-path}.

@defopt TeX-check-path
Directory path to search for dependencies.

If nil, just check the current file.
Used when checking if any files have changed.
@end defopt

@cindex ispell
When performing spell checking on a document or a region (invoked
through @AUCTeX{}'s @samp{Spell} command or @kbd{M-x ispell @key{RET}}), you
want the spell checking program to skip certain macro arguments and
environments, most notably the arguments of referencing macros and the
contents of verbatim environments.  The skipped parts are controlled by
variable @code{ispell-tex-skip-alists} provided by @file{ispell.el}.
@AUCTeX{} has a library which can be added to this variable depending on
the value of @code{TeX-ispell-extend-skip-list} which is set to @code{t}
by default.

@defopt TeX-ispell-extend-skip-list
This boolean option controls whether @AUCTeX{} activates its extension
for skipping certain macro arguments and environments when spell
checking.

When non-@code{nil}, @AUCTeX{} loads the file @file{tex-ispell.el} and
adds its content to @code{ispell-tex-skip-alists}.  This library can and
will never be complete, but the interface can be used to add selected
and private macro names within your init file or on a file local basis.

@code{ispell-tex-skip-alists} has the following structure:
@lisp
(defvar ispell-tex-skip-alists
  '((;; @r{First list}
     ("\\\\addcontentsline"         ispell-tex-arg-end 2)
     ("\\\\\\([aA]lph\\|arabic\\)"  ispell-tex-arg-end)
     ("\\\\makebox"                 ispell-tex-arg-end 0)
     ("\\\\documentclass" . "\\\\begin@{document@}"))
    (;; @r{Second list}
     ("\\(figure\\|table\\)\\*?"  ispell-tex-arg-end 0)
     ("list"                      ispell-tex-arg-end 2)
     ("verbatim\\*?" . "\\\\end@{verbatim\\*?@}")))
  "Lists of regions to be skipped in TeX mode.
First list is used raw.
Second list has key placed inside \\begin@{@}.")
@end lisp
Each item is an alist and the structure of it is described in
@code{ispell-skip-region-alist}:
@lisp
(defvar ispell-skip-region-alist
  '((...))
  "Alist expressing beginning and end of regions not to spell check.
The alist key must be a regular expression.
Valid forms include:
  (KEY) - just skip the key.
  (KEY . REGEXP) - skip to the end of REGEXP.
                   REGEXP may be string or symbol.
  (KEY REGEXP) - skip to end of REGEXP.  REGEXP must be a string.
  (KEY FUNCTION ARGS) - FUNCTION called with ARGS
                        returns end of region.")
@end lisp

Let's go through the first list of @code{ispell-tex-skip-alists} line by
line:
@lisp
("\\\\addcontentsline"         ispell-tex-arg-end 2)
@end lisp
@code{KEY} is the string @code{"\\\\addcontentsline"}, @code{FUNCTION}
is @code{ispell-tex-arg-end} called with @code{ARGS}, here @code{2}.
@code{ispell-tex-arg-end} is a function provided by @file{ispell.el}
which skips as many subsequent optional arguments in square brackets as
it sees and then skips @code{ARGS} number of mandatory arguments in
braces.  Omitting @code{ARGS} means skip @code{1} mandatory argument.
In practice, when you have something like this in your document:
@example
\addcontentsline@{toc@}@{chapter@}@{Some text@}
@end example
The first two arguments are left out and @samp{Some text} will be spell
checked.  For the next line
@lisp
("\\\\\\([aA]lph\\|arabic\\)"  ispell-tex-arg-end)
@end lisp
the name of the counter as argument is skipped.  Next line is
@lisp
("\\\\makebox"                 ispell-tex-arg-end 0)
@end lisp
where only optional arguments are skipped, the first mandatory argument
is checked, e.g.
@example
\makebox[0pt][l]@{Some text@}
@end example
Finally, the next line
@lisp
("\\\\documentclass" . "\\\\begin@{document@}"))
@end lisp
ensures that the entire preamble of a document is discarded.  Second
list works the same; it is more convenient for environments since
@code{KEY} is wrapped inside @code{\begin@{@}}.

@findex TeX-ispell-skip-setcar
@findex TeX-ispell-skip-setcdr
@AUCTeX{} provides two functions to add items to car and cdr of
@code{ispell-tex-arg-end}, namely @code{TeX-ispell-skip-setcar} and
@code{TeX-ispell-skip-setcdr}.  The argument of these functions is
exactly as in @code{ispell-tex-skip-alists}.  Additions can be done via
init file, e.g.:
@lisp
(eval-after-load "tex-ispell"
  '(progn
     (TeX-ispell-skip-setcar
      '(("\\\\mymacro" ispell-tex-arg-end)))
     (TeX-ispell-skip-setcdr
      '(("myverbatim" . "\\\\end@{myverbatim@}")))))
@end lisp

Another possibility is to use file local additions at the end of your
@TeX{} file, e.g.:
@example
%%% Local Variables:
%%% mode: latex
%%% TeX-master: t
%%% eval: (TeX-ispell-skip-setcar '(("\\\\mymacro" . "@{[-0-9]+@}")))
%%% End:
@end example

@findex TeX-ispell-tex-arg-end
Finally, @AUCTeX{} provides a function called
@code{TeX-ispell-tex-arg-end} which sees more arguments than
@code{ispell-tex-arg-end}.  Refer to its doc string for more
information.
@end defopt

@AUCTeX{} also provides a facility to skip the argument of in-line
verbatim macros like @samp{\Verb} from @file{fancyvrb.sty} or
@samp{\mintinline} from @file{minted.sty}.  Characters delimiting the
verbatim text are stored in @code{TeX-ispell-verb-delimiters}.

@defopt TeX-ispell-verb-delimiters
String with delimiters recognized for in-line verbatim macros.  This
variable is initialized to @samp{!|#~"*/+^-}.  Since this string is
used to build a character alternative inside a regular expression,
special characters @samp{^} and @samp{-} should come last.  Other
characters like opening brace @samp{@{}, asterisk @samp{*} or at sign
@samp{@@} should be avoided as they are not recognized by
@file{font-latex.el}.
@end defopt

@node Processor Options
@subsection Options for @TeX{} Processors

There are some options you can customize affecting which processors are
invoked or the way this is done and which output they produce as a
result.  These options control if @acronym{DVI} or @acronym{PDF} output
should be produced, if @TeX{} should be started in interactive or
nonstop mode, if source specials or a Sync@TeX{} file should be produced
for making inverse and forward search possible or which @TeX{} engine
should be used instead of regular @TeX{}, like PDF@TeX{}, Omega or
Xe@TeX{}, and the style error messages are printed with.

@deffn Command TeX-PDF-mode
@kindex C-c C-t C-p
@vindex TeX-PDF-mode
@cindex PDF mode
(@kbd{C-c C-t C-p})
This command toggles the @acronym{PDF} mode of @AUCTeX{}, a buffer-local
minor mode which is enabled by default.  You can customize
@code{TeX-PDF-mode} to give it a different default or set it as a file
local variable on a per-document basis.  This option usually results in
calling either PDF@TeX{} or ordinary @TeX{}.
@end deffn

@defopt TeX-DVI-via-PDFTeX
If this is set, @acronym{DVI} will also be produced by calling
PDF@TeX{}, setting @code{\pdfoutput=0}.  This makes it possible to use
PDF@TeX{} features like character protrusion even when producing
@acronym{DVI} files.  Contemporary @TeX{} distributions do this anyway,
so that you need not enable the option within @AUCTeX{}.
@end defopt

@deffn Command TeX-interactive-mode
@kindex C-c C-t C-i
@vindex TeX-interactive-mode
(@kbd{C-c C-t C-i}) This command toggles the interactive mode of
@AUCTeX{}, a global minor mode.  You can customize
@code{TeX-interactive-mode} to give it a different default.  In
interactive mode, @TeX{} will pause with an error prompt when errors are
encountered and wait for the user to type something.
@end deffn

@cindex I/O correlation
@cindex Sync@TeX{}
@cindex Source specials
@cindex PDFSync
@deffn Command TeX-source-correlate-mode
@kindex C-c C-t C-s
@vindex TeX-source-correlate-mode
(@kbd{C-c C-t C-s}) Toggles support for forward and inverse search.
Forward search refers to jumping to the place in the previewed document
corresponding to where point is located in the document source and
inverse search to the other way round.  @xref{I/O Correlation}.

You can permanently activate @code{TeX-source-correlate-mode} by
customizing the variable @code{TeX-source-correlate-mode}.  There is a
bunch of customization options for the mode, use @kbd{M-x
customize-group @key{RET} TeX-view @key{RET}} to find out more.

@vindex TeX-source-correlate-method
@AUCTeX{} is aware of three different means to do I/O correlation:
source specials (only DVI output), the pdfsync @LaTeX{} package (only
PDF output) and Sync@TeX{}.  The choice between source specials and
Sync@TeX{} can be controlled with the variable
@code{TeX-source-correlate-method}.

Should you use source specials it has to be stressed @emph{very}
strongly however, that source specials can cause differences in page
breaks and spacing, can seriously interfere with various packages and
should thus @emph{never} be used for the final version of a document.
In particular, fine-tuning the page breaks should be done with source
specials switched off.
@end deffn

Sometimes you are requested, by journal rules or packages, to compile
the document into @acronym{DVI} output.  Thus, if you want a
@acronym{PDF} document in the end you can either use Xe@TeX{} engine,
see below for information about how to set engines, or compile the
document with @command{tex} and then convert to @acronym{PDF} with
@command{dvips}--@command{ps2pdf} before viewing it.  In addition,
current Japanese @TeX{} engines cannot generate @acronym{PDF} directly
so they rely on @acronym{DVI}-to-@acronym{PDF} converters.  Usually
@command{dvipdfmx} command is used for this purpose.  You can use the
@code{TeX-PDF-from-DVI} variable to let @AUCTeX{} know you want to
generate the final @acronym{PDF} by converting a @acronym{DVI} file.

@defopt TeX-PDF-from-DVI
This option controls if and how to produce a @acronym{PDF} file by
converting a @acronym{DVI} file.

When @code{TeX-PDF-mode} is non-nil, if @code{TeX-PDF-from-DVI} is
non-nil too the document is compiled to @acronym{DVI} instead of
@acronym{PDF}.  When the document is ready, @kbd{C-c C-c} will suggest
to run the converter to @acronym{PDF} or an intermediate format.

If non-nil, @code{TeX-PDF-from-DVI} should be the name of the command in @code{TeX-command-list},
as a string, used to convert the @acronym{DVI} file to @acronym{PDF} or
to an intermediate format.  Values currently supported are:
@itemize
@item
@code{"Dvips"}: the @acronym{DVI} file is converted to @acronym{PS} with
@command{dvips}.  After successfully running it, @command{ps2pdf} will
be the default command to convert the @acronym{PS} file to
@acronym{PDF}.
@item
@code{"Dvipdfmx"}: the @acronym{DVI} file is converted to @acronym{PDF}
with @command{dvipdfmx}.
@end itemize
(case is significant; note the uppercase @samp{D} in both strings)
When the @acronym{PDF} file is finally ready, the next suggested command
will be @samp{View} to open the viewer.

This option can also be set as a file local variable, in order to use
this conversion on a per-document basis.

Recall the whole sequence of @kbd{C-c C-c} commands can be replaced by
the single @kbd{C-c C-a}.
@end defopt

@AUCTeX{} also allows you to easily select different @TeX{} engines for
processing, either by using the entries in the @samp{TeXing Options}
submenu below the @samp{Command} menu or by calling the function
@code{TeX-engine-set}.  These eventually set the variable
@code{TeX-engine} which you can also modify directly.

@defopt TeX-engine
This variable allows you to choose which @TeX{} engine should be used
for typesetting the document, i.e.@: the executables which will be used
when you invoke the @samp{TeX} or @samp{LaTeX} commands.  The value
should be one of the symbols defined in @code{TeX-engine-alist-builtin}
or @code{TeX-engine-alist}.  The symbols @samp{default}, @samp{xetex},
@samp{luatex} and @samp{omega} are available from the built-in list.
@end defopt

Note that @code{TeX-engine} is buffer-local, so setting the variable
directly or via the above mentioned menu or function will not take
effect in other buffers.  If you want to activate an engine for all
@AUCTeX{} modes, set @code{TeX-engine} in your init file, e.g.@: by using
@kbd{M-x customize-option @key{RET}}.  If you want to activate it for a
certain @AUCTeX{} mode only, set the variable in the respective mode
hook.  If you want to activate it for certain files, set it through file
variables (@pxref{File Variables,,,emacs,The Emacs Editor}).

@vindex TeX-command
@vindex LaTeX-command
@vindex TeX-Omega-command
@vindex LaTeX-Omega-command
@vindex ConTeXt-engine
@vindex ConTeXt-Omega-engine
@vindex TeX-engine-alist
@vindex TeX-engine-alist-builtin
Should you need to change the executable names related to the different
engine settings, there are some variables you can tweak.  Those are
@code{TeX-command}, @code{LaTeX-command}, @code{TeX-Omega-command},
@code{LaTeX-Omega-command}, @code{ConTeXt-engine} and
@code{ConTeXt-Omega-engine}.  The rest of the executables is defined
directly in @code{TeX-engine-alist-builtin}.  If you want to override an
entry from that, add an entry to @code{TeX-engine-alist} that starts
with the same symbol as that the entry in the built-in list and specify
the executables you want to use instead.  You can also add entries to
@code{TeX-engine-alist} in order to add support for engines not covered
per default.

@defopt TeX-engine-alist
Alist of @TeX{} engines and associated commands.  Each entry is a list with
a maximum of five elements.  The first element is a symbol used to
identify the engine.  The second is a string describing the engine.  The
third is the command to be used for plain @TeX{}.  The fourth is the
command to be used for @LaTeX{}.  The fifth is the command to be used for
the @option{--engine} parameter of @ConTeXt{}'s @samp{texexec} program.  Each
command can either be a variable or a string.  An empty string or nil
means there is no command available.
@end defopt

In some systems, Emacs cannot inherit the @env{PATH} environment variable from
the shell and thus @AUCTeX{} may not be able to run @TeX{} commands.
Before running them, @AUCTeX{} checks if it is able to find those commands
and will warn you in case it fails.  You can skip this test by changing
the option @code{TeX-check-TeX}.

@defopt TeX-check-TeX
@vindex TeX-command
@vindex TeX-check-TeX-command-not-found
If non-nil, @AUCTeX{} will check if it is able to find a working @TeX{}
distribution before running @TeX{}, @LaTeX{}, @ConTeXt{}, etc.  It
actually checks if can run @code{TeX-command} command or the shell
returns a command not found error.  The error code returned by the shell
in this case can be set in @code{TeX-check-TeX-command-not-found}
option.
@end defopt

Some @LaTeX{} packages requires the document to be compiled with a
specific engine.  Notable examples are @samp{fontspec} and @samp{polyglossia}
packages, which require Lua@TeX{} and Xe@TeX{} engines.  If you try to
compile a document which loads one of such packages and the set engine
is not one of those allowed you will be asked to select a different
engine before running the @LaTeX{} command.  If you do not want to be
warned by @AUCTeX{} in these cases, customize the option
@code{TeX-check-engine}.

@defopt TeX-check-engine
This boolean option controls whether @AUCTeX{} should check the correct
engine has been set before running @LaTeX{} commands.
@end defopt

As shown above, @AUCTeX{} handles in a special way most of the main
options that can be given to the @TeX{} processors.  When you need to
pass to the @TeX{} processor arbitrary options not handled by @AUCTeX{},
you can use the file local variable @code{TeX-command-extra-options}.
@defopt TeX-command-extra-options
String with the extra options to be given to the TeX processor.  For
example, if you need to enable the shell escape feature to compile a
document, add the following line to the list of local variables of the
source file:
@example
%%% TeX-command-extra-options: "-shell-escape"
@end example
By default this option is not safe as a file-local variable because a
specially crafted document compiled with shell escape enabled can be
used for malicious purposes.
@end defopt

You can customize @AUCTeX{} to show the processor output as it is
produced.

@defopt TeX-show-compilation
If non-nil, the output of @TeX{} compilation is shown in another window.
@end defopt

You can instruct @TeX{} to print error messages in the form
@samp{file:line:error} which is similar to the way many compilers format them.

@defopt TeX-file-line-error
If non-nil, @TeX{} will produce @samp{file:line:error} style error messages.
@end defopt

@ConTeXt{} users can choose between Mark II and Mark IV versions.  This
is controlled by @code{ConTeXt-Mark-version} option.

@defopt ConTeXt-Mark-version
This variables specifies which version of Mark should be used.  Values
currently supported are @code{"II"}, the default, and @code{"IV"}.  It
can be set globally using customization interface or on a per-file
basis, by specifying it as a file variable.
@end defopt

@node Viewing
@section Viewing the Formatted Output
@cindex Viewing
@cindex Previewing
@cindex Starting a previewer

@AUCTeX{} allows you to start external programs for previewing the
formatted output of your document.

@menu
* Starting Viewers::            Starting viewers
* I/O Correlation::             Forward and inverse search
@end menu

@node Starting Viewers
@subsection Starting Viewers

Viewers are normally invoked by pressing @kbd{C-c C-c} once the document
is formatted, which will propose the @samp{View} command, or by activating the
respective entry in the Command menu.  Alternatively you can type
@kbd{C-c C-v} which calls the function @code{TeX-view}.

@deffn Command TeX-view
@kindex C-c C-v
(@kbd{C-c C-v}) Start a viewer without confirmation.  The viewer is
started either on a region or the master file, depending on the last
command issued.  This is especially useful for jumping to the location
corresponding to point in the viewer when using
@code{TeX-source-correlate-mode}.
@end deffn

@AUCTeX{} will try to guess which type of viewer (@acronym{DVI},
PostScript or @acronym{PDF}) has to be used and what options are to be
passed over to it.  This decision is based on the output files present
in the working directory as well as the class and style options used in
the document.  For example, if there is a @acronym{DVI} file in your
working directory, a @acronym{DVI} viewer will be invoked.  In case of a
@acronym{PDF} file it will be a @acronym{PDF} viewer.  If you specified
a special paper format like @samp{a5paper} or use the @samp{landscape}
option, this will be passed to the viewer by the appropriate options.
Especially some @acronym{DVI} viewers depend on this kind of information
in order to display your document correctly.  In case you are using
@samp{pstricks} or @samp{psfrag} in your document, a @acronym{DVI}
viewer cannot display the contents correctly and a PostScript viewer
will be invoked instead.

The association between the tests for the conditions mentioned above and
the viewers is made in the variable @code{TeX-view-program-selection}.
Therefore this variable is the starting point for customization if you
want to use other viewers than the ones suggested by default.

@defopt TeX-view-program-selection
This is a list of predicates and viewers which is evaluated from front
to back in order to find out which viewer to call under the given
conditions.  In the first element of each list item you can reference
one or more predicates defined in @code{TeX-view-predicate-list} or
@code{TeX-view-predicate-list-builtin}.  In the second element you can
reference a viewer defined in @code{TeX-view-program-list} or
@code{TeX-view-program-list-builtin}.  The viewer of the first item with
a positively evaluated predicate is selected.
@end defopt

So @code{TeX-view-program-selection} only contains references to the
actual implementations of predicates and viewer commands respectively
which can be found elsewhere.  @AUCTeX{} comes with a set of
preconfigured predicates and viewer commands which are stored in the
variables @code{TeX-view-predicate-list-builtin} and
@code{TeX-view-program-list-builtin} respectively.  If you are not
satisfied with those and want to overwrite one of them or add your own
definitions, you can do so via the variables
@code{TeX-view-predicate-list} and @code{TeX-view-program-list}.

@defopt TeX-view-predicate-list
This is a list of predicates for viewer selection and invocation.  The
first element of each list item is a symbol and the second element a
Lisp form to be evaluated.  The form should return nil if the predicate
is not fulfilled.

A built-in predicate from @code{TeX-view-predicate-list-builtin} can be
overwritten by defining a new predicate with the same symbol.
@end defopt

@defopt TeX-view-program-list
This is a list of viewer specifications each consisting of a symbolic
name and either a command line or a function to be invoked when the
viewer is called.  If a command line is used, parts of it can be
conditionalized by prefixing them with predicates from
@code{TeX-view-predicate-list} or
@code{TeX-view-predicate-list-builtin}.  (See the doc string for the
exact format to use.)  The command line can also contain placeholders as
defined in @code{TeX-expand-list} and @code{TeX-expand-list-builtin}
which are expanded before the viewer is called.

The third element of each item is a string, or a list of strings, with
the name of the executable, or executables, needed to open the output
file in the viewer.  Placeholders defined in @code{TeX-expand-list} and
@code{TeX-expand-list-builtin} can be used here.  This element is
optional and is used to check whether the viewer is actually available
on the system.

A built-in viewer spec from @code{TeX-view-program-list-builtin} can be
overwritten by defining a new viewer spec with the same name.
@end defopt

After the viewer is called via either the @samp{View} command or the key stroke
@kbd{C-c C-v}, the window system focus goes and stays on the viewer.  If
you prefer that the focus is pulled back to Emacs immediately after that
and you are using evince-compatible viewer, customize the option
@code{TeX-view-enince-keep-focus}.

@defopt TeX-view-evince-keep-focus
When this option is non-nil and the viewer is compatible with evince,
the focus is pulled back to Emacs immediately after the viewer is
invoked or refreshed from within @AUCTeX{}.
@end defopt

Note that the viewer selection and invocation as described above will
only work if certain default settings in @AUCTeX{} are intact.  For one,
the whole viewer selection machinery will only be triggered if there is
no @samp{%V} expander in @code{TeX-expand-list}.  So if you have trouble
with the viewer invocation you might check if there is an older
customization of the variable in place.  In addition, the use of a
function in @code{TeX-view-program-list} only works if the @samp{View} command
in @code{TeX-command-list} makes use of the hook
@code{TeX-run-discard-or-function}.

@node I/O Correlation
@subsection Forward and Inverse Search
@cindex Inverse search
@cindex Forward search
@cindex I/O correlation
@cindex Source specials
@cindex Sync@TeX{}
@cindex PDFSync

Forward and inverse search refer to the correlation between the document
source in the editor and the typeset document in the viewer.  Forward
search allows you to jump to the place in the previewed document
corresponding to a certain line in the document source and inverse
search vice versa.

@findex TeX-source-correlate-mode
@AUCTeX{} supports three methods for forward and inverse search: source
specials (only @acronym{DVI} output), the pdfsync @LaTeX{} package (only @acronym{PDF}
output) and Sync@TeX{} (any type of output).  If you want to make use of
forward and inverse searching with source specials or Sync@TeX{}, switch
on @code{TeX-source-correlate-mode}.  @xref{Processor Options}, on how
to do that.  The use of the pdfsync package is detected automatically if
document parsing is enabled.  Customize the variable
@code{TeX-source-correlate-method} to select the method to use.

@defopt TeX-source-correlate-method
Method to use for enabling forward and inverse search.  This can be
@samp{source-specials} if source specials should be used, @samp{synctex}
if Sync@TeX{} should be used, or @samp{auto} if @AUCTeX{} should decide.

When the variable is set to @samp{auto}, @AUCTeX{} will always use
Sync@TeX{} if your @command{latex} processor supports it, source specials
otherwise.  You must make sure your viewer supports the same method.

It is also possible to specify a different method depending on the
output, either @acronym{DVI} or @acronym{PDF}, by setting the variable to an alist of the
kind
@lisp
((dvi . @samp{<source-specials or synctex>})
 (pdf . @samp{<source-specials or synctex>}))
@end lisp
in which the CDR of each entry is a symbol specifying the method to be
used in the corresponding mode.  The default value of the variable is
@lisp
((dvi . source-specials)
 (pdf . synctex))
@end lisp
which is compatible with the majority of viewers.
@end defopt

@findex TeX-view
Forward search happens automatically upon calling the viewer, e.g.@: by
typing @kbd{C-c C-v} (@code{TeX-view}).  This will open the viewer or
bring it to front and display the output page corresponding to the
position of point in the source file.  @AUCTeX{} will automatically pass
the necessary command line options to the viewer for this to happen.

@vindex TeX-source-correlate-start-server
Upon opening the viewer you will be asked if you want to start a server
process (Gnuserv or Emacs server) which is necessary for inverse search.
This happens only if there is no server running already.  You can
customize the variable @code{TeX-source-correlate-start-server} to
inhibit the question and always or never start the server respectively.

@defopt TeX-source-correlate-start-server
If @code{TeX-source-correlate-mode} is active and a viewer is invoked,
the default behavior is to ask if a server process should be started.
Set this variable to @code{t} if the question should be inhibited and
the server should always be started.  Set it to @code{nil} if the server
should never be started.  Inverse search will not be available in the
latter case.
@end defopt

Inverse search, i.e.@: jumping to the part of your document source in
Emacs corresponding to a certain position in the viewer, is triggered
from the viewer, typically by a mouse click.  Refer to the documentation
of your viewer to find out how it has to be configured and what you have
to do exactly.  In xdvi you normally have to use @kbd{C-down-mouse-1}.

@vindex TeX-source-correlate-start-server
Note that inverse search with the Evince @acronym{PDF} viewer or its MATE fork
Atril might fail in raising the Emacs frame after updating point in your
document's buffer.  There is simply no way to raise the Emacs frame
reliably accross different operating systems and different window
managers with their different focus stealing policies.  If the Emacs
frame is not raised after performing an inverse search from Evince or
Atril, you can customize the following option.

@defopt TeX-raise-frame-function
A function that will be called after performing an inverse search from
Evince or Atril in order to raise the current Emacs frame.

If your Emacs frame is already raised in that situation, just
leave this variable set to its default value
@code{raise-frame}.  Otherwise, here are some alternative
settings that work for some users.

@lisp
;; @r{Alternative 1: For some users, @t{`x-focus-frame'} works.}
(setq TeX-raise-frame-function #'x-focus-frame)

;; @r{Alternative 2: Under GNOME 3.20 (and probably others), it}
;; @r{seems some focus stealing prevention policy prohibits that}
;; @r{some window gets the focus immediately after the user has}
;; @r{clicked in some other window.  Here waiting a bit before}
;; @r{issuing the request seems to work.}
(setq TeX-raise-frame-function
      (lambda ()
        (run-at-time 0.5 nil #'x-focus-frame)))

;; @r{Alternative 3: Use the external @t{wmctrl} tool in order to}
;; @r{force Emacs into the focus.}
(setq TeX-raise-frame-function
      (lambda ()
        (call-process
         "wmctrl" nil nil nil "-i" "-R"
         (frame-parameter (selected-frame) 'outer-window-id))))
@end lisp
@end defopt


@node Debugging
@section Catching the errors
@cindex Debugging
@cindex Errors
@cindex Parsing errors
@cindex Parsing @TeX{} output
@cindex Next error
@cindex Parsing @LaTeX{} errors
@cindex Overfull boxes
@cindex Bad boxes
@cindex Underfull boxes

Once you've formatted your document you may `debug' it, i.e.@: browse
through the errors (La)@TeX{} reported.  You may also have a look at a
nicely formatted list of all errors and warnings reported by the
compiler.

@deffn Command TeX-next-error @var{arg} @var{reparse}
@kindex C-c `
(@kbd{C-c `})  Go to the next error reported by @TeX{}.  The view will
be split in two, with the cursor placed as close as possible to the
error in the top view.  In the bottom view, the error message will be
displayed along with some explanatory text.

An optional numeric @var{arg}, positive or negative, specifies how many
error messages to move.  A negative @var{arg} means to move back to
previous error messages, see also @code{TeX-previous-error}.

The optional @var{reparse} argument makes @AUCTeX{} reparse the error
message buffer and start the debugging from the first error.  This can
also be achieved by calling the function with a prefix argument
(@kbd{C-u}).
@end deffn

@deffn Command TeX-previous-error @var{arg}
@kindex M-g p
(@kbd{M-g p}) Go to the previous error reported by @TeX{}.  An optional
numeric @var{arg} specifies how many error messages to move backward.
This is like calling @code{TeX-next-error} with a negative argument.
@end deffn

The command @code{TeX-previous-error} works only if @AUCTeX{} can parse
the whole @TeX{} log buffer.  This is controlled by the
@code{TeX-parse-all-errors} variable.

@defopt TeX-parse-all-errors
If t, @AUCTeX{} automatically parses the whole output log buffer right
after running a @TeX{} command, in order to collect all warnings and
errors.  This makes it possible to navigate back and forth between the
error messages using @code{TeX-next-error} and
@code{TeX-previous-error}.  This is the default.  If nil, @AUCTeX{} does
not parse the whole output log buffer and @code{TeX-previous-error}
cannot be used.
@end defopt

As default, @AUCTeX{} will display a special help buffer containing the
error reported by @TeX{} along with the documentation.  There is however
an `expert' option, which allows you to display the real @TeX{} output.

@defopt TeX-display-help
If t @AUCTeX{} will automatically display a help text whenever an error
is encountered using @code{TeX-next-error} (@kbd{C-c `}).  If nil a
terse information about the error is displayed in the echo area.  If
@code{expert} @AUCTeX{} will display the output buffer with the raw
@TeX{} output.
@end defopt

@menu
* Ignoring warnings::         Controlling warnings to be reported
* Error overview::            List of all errors and warnings
@end menu

@node Ignoring warnings
@subsection Controlling warnings to be reported

Normally @AUCTeX{} will only report real errors, but you may as well
ask it to report `bad boxes' and warnings as well.

@deffn Command TeX-toggle-debug-bad-boxes
@kindex C-c C-t C-b
@vindex TeX-debug-bad-boxes
(@kbd{C-c C-t C-b}) Toggle whether @AUCTeX{} should stop at bad boxes
(i.e.@: overfull and underfull boxes) as well as normal errors.  The
boolean option @code{TeX-debug-bad-boxes} is set accordingly.
@end deffn

@deffn Command TeX-toggle-debug-warnings
@kindex C-c C-t C-w
@vindex TeX-debug-warnings
(@kbd{C-c C-t C-w}) Toggle whether @AUCTeX{} should stop at warnings as
well as normal errors.  The boolean option @code{TeX-debug-warnings} is
set accordingly.
@end deffn

While many users desire to have warnings reported after compilation,
there are certain warnings that are considered unimportant and users
want to ignore them.  For a more fine-grained control of what kinds of
warnings should be shown after compilation, @AUCTeX{} provides other
options.

@defopt TeX-ignore-warnings
Controls which warnings are to be ignored.

It can be a regexp matching the message of the warnings to be ignored.

More advanced users can set also this option to a symbol with the name
of a custom function taking as arguments all the information of the
warning listed in @code{TeX-error-list} variable, except the last one
about whether to ignore the warning.  See the code of @code{TeX-warning}
function and the documentation of @code{TeX-error-list} for more
details.
@end defopt

@deffn Command TeX-toggle-suppress-ignored-warnings
@kindex C-c C-t C-x
@vindex TeX-suppress-ignored-warnings
(@kbd{C-c C-t C-x}) Toggle whether @AUCTeX{} should actually hide the
ignored warnings specified with @code{TeX-ignore-warnings}.  The boolean
option @code{TeX-suppress-ignored-warnings} is set accordingly.  If this
is nil, all warnings are shown, even those matched by
@code{TeX-ignore-warnings}, otherwise these are hidden.

Note that @code{TeX-debug-warnings} takes the precedence: if it is nil,
all warnings are hidden in any case.
@end deffn

@node Error overview
@subsection List of all errors and warnings

When the option @code{TeX-parse-all-errors} is non-nil, you will be also
able to open an overview of all errors and warnings reported by the @TeX{}
compiler.

@deffn Command TeX-error-overview
Show an overview of the errors and warnings occurred in the last @TeX{}
run.

In this window you can visit the error on which point is by pressing
@key{RET}, and visit the next or previous issue by pressing @key{n} or
@key{p} respectively.  A prefix argument to these keys specifies how
many errors to move forward or backward.  You can visit an error also by
clicking on its message.  Jump to error point in the source code with
@key{j}, and use @key{l} see the error in the log buffer.  In addition,
you can toggle visibility of bad boxes, generic warnings, and ignored
warnings with @key{b}, @key{w}, and @key{x}, respectively (see
@ref{Ignoring warnings} for details).  Press @key{q} to quit the
overview.
@end deffn

@defopt TeX-error-overview-open-after-TeX-run
When this boolean variable is non-nil, the error overview will be
automatically opened after running @TeX{} if there are errors or warnings
to show.
@end defopt

The error overview is opened in a new window of the current frame by
default, but you can change this behavior by customizing the option
@code{TeX-error-overview-setup}.

@defopt TeX-error-overview-setup
Controls the frame setup of the error overview.  The possible value is:
@code{separate-frame}; with a nil value the current frame is used
instead.

The parameters of the separate frame can be set with the
@code{TeX-error-overview-frame-parameters} option.

If the display does not support multi frame, the current frame
will be used regardless of the value of this variable.
@vindex TeX-error-overview-frame-parameters
@end defopt

@node Checking
@section Checking for problems
@cindex Checking
@cindex @code{lacheck}
@cindex @code{chktex}
@cindex Finding errors
@cindex Running @code{lacheck}
@cindex Running @code{chktex}
@cindex Style
@cindex Problems
@cindex Flymake
@cindex Running Flymake

Running @TeX{} or @LaTeX{} will only find regular errors in the
document, not examples of bad style.  Furthermore, description of the
errors may often be confusing.  The utilities @code{lacheck} and
@code{chktex} can be used to find style errors, such as forgetting to
escape the space after an abbreviation or using @samp{...} instead of
@samp{\ldots} and other similar problems.  You start @code{lacheck} with
@kbd{C-c C-c Check @key{RET}} and @code{chktex} with @kbd{C-c C-c ChkTeX
@key{RET}}.  The result will be a list of errors in the
@samp{*compilation*} buffer.  You can go through the errors with
@kbd{C-x `} (@code{next-error}, @pxref{Compilation,,,emacs,The Emacs
Editor}), which will move point to the location of the next error.

Alternatively, you may want in-buffer notation.  @AUCTeX{} provides
support for this using the Flymake package in Emacs 26 or newer
(@pxref{Using Flymake,,,Flymake,GNU Flymake} for details).  To enable,
call @kbd{M-x flymake-mode @key{RET}} in the buffer or enable it in all
buffers by adding this to your init file:
@lisp
(add-hook 'LaTeX-mode-hook #'flymake-mode)
@end lisp
Note that @AUCTeX{} currently only provides support for using
@code{chktex} as the flymake backend.

Each of the two utilities @code{lacheck} and @code{chktex} will find
some errors the other doesn't, but @code{chktex} is more configurable,
allowing you to create your own errors.  You may need to install the
programs before using them.  You can get @code{lacheck} from
URL:@url{https://www.ctan.org/pkg/lacheck} and
@code{chktex} from
URL:@url{https://www.ctan.org/pkg/chktex}.  @w{@TeX{} Live} contains
both.

@node Control
@section Controlling the output
@cindex Controlling the output
@cindex Output
@cindex Redisplay output
@cindex Processes
@cindex Killing a process
@cindex Finding the master file
@cindex Master file
@cindex Stopping a process
@cindex Current file
@cindex Finding the current file

A number of commands are available for controlling the output of an
application running under @AUCTeX{}

@deffn Command TeX-kill-job
@kindex C-c C-k
(@kbd{C-c C-k})  Kill currently running external application.
This may be either of @TeX{}, @LaTeX{}, previewer, Bib@TeX{}, etc.
@end deffn

@deffn Command TeX-recenter-output-buffer
@kindex C-c C-l
(@kbd{C-c C-l})  Recenter the output buffer so that the bottom line is
visible.
@end deffn

@deffn Command TeX-home-buffer
@kindex C-c ^
(@kbd{C-c ^}) Go to the `master' file in the document associated with
the current buffer, or if already there, to the file where the current
process was started.
@end deffn

Additionally, output files produced by @AUCTeX{} can be placed in a
separate directory.

@defopt TeX-output-dir
Set this option to the path of a directory where output files will be
placed.  The output files include those that are produced by applications
running under @AUCTeX{}, temporary files related to region processing and
the @previewlatex{} files.  If a relative path is specified, it is
interpreted as being relative to the master file in a mutlifile document.

This is a buffer local variable and must be set separately for all
documents and all files in a multifile document.  For example,

@example
%%% Local Variables:
%%% mode: latex
%%% TeX-output-dir: "build"
%%% End:
@end example

Alternatively, you may use @code{setq-default} to set the default value of
this option or set it as a directory local variable (@pxref{Directory
Variables,,, emacs, The Emacs Editor}).

Note that a non-nil value of @code{TeX-output-dir} might be incompatible
with some @TeX{} commands and macros.  In particular, the @LaTeX{} macro
@samp{\include} is known to not work with this option.  Some @TeX{}
packages which produce intermediary files might also be incompatible.  A
possible workaround for those packages is to append the value of
@code{TeX-output-dir} to the environment variables @env{TEXINPUTS} and
@env{BIBINPUTS}.
@end defopt

@node Cleaning
@section Cleaning intermediate and output files
@cindex Cleaning

@deffn Command TeX-clean
@vindex plain-TeX-clean-intermediate-suffixes
@vindex plain-TeX-clean-output-suffixes
@vindex LaTeX-clean-intermediate-suffixes
@vindex LaTeX-clean-output-suffixes
@vindex docTeX-clean-intermediate-suffixes
@vindex docTeX-clean-output-suffixes
@vindex Texinfo-clean-intermediate-suffixes
@vindex Texinfo-clean-output-suffixes
@vindex ConTeXt-clean-intermediate-suffixes
@vindex ConTeXt-clean-output-suffixes
@vindex AmSTeX-clean-intermediate-suffixes
@vindex AmSTeX-clean-output-suffixes
Remove generated intermediate files.  In case a prefix argument is
given, remove output files as well.

Canonical access to the function is provided by the @samp{Clean} and
@samp{Clean All} entries in @code{TeX-command-list}, invokable with
@kbd{C-c C-c} or the Command menu.

The patterns governing which files to remove can be adapted separately
for each @AUCTeX{} mode by means of the following variables:
@itemize
@item
@code{plain-TeX-clean-intermediate-suffixes}
@item
@code{plain-TeX-clean-output-suffixes}
@item
@code{LaTeX-clean-intermediate-suffixes}
@item
@code{LaTeX-clean-output-suffixes}
@item
@code{docTeX-clean-intermediate-suffixes}
@item
@code{docTeX-clean-output-suffixes}
@item
@code{Texinfo-clean-intermediate-suffixes}
@item
@code{Texinfo-clean-output-suffixes}
@item
@code{ConTeXt-clean-intermediate-suffixes}
@item
@code{ConTeXt-clean-output-suffixes}
@item
@code{AmSTeX-clean-intermediate-suffixes}
@item
@code{AmSTeX-clean-output-suffixes}
@end itemize

@end deffn

@defopt TeX-clean-confirm
Control if deletion of intermediate and output files has to be confirmed
before it is actually done.  If non-nil, ask before deleting files.
@end defopt

@node Documentation
@section Documentation about macros and packages
@cindex Documentation

@deffn Command TeX-documentation-texdoc
@kindex C-c ?
(@kbd{C-c ?})  Get documentation about the packages installed on your
system, using @command{texdoc} to find the manuals.  The function will
prompt for the name of packages.  If point is on a word, this will be
suggested as default.

If the command is called with a prefix argument, you will be shown a
list of manuals of the given package among to choose.

The command can be invoked by the key binding mentioned above as well as
the @samp{Find Documentation...} entry in the mode menu.
@end deffn

@node Customization
@chapter Customization and Extension

@menu
* Modes and Hooks::             Modes and Hooks
* Multifile::                   Multifile Documents
* Parsing Files::               Automatic Parsing of @TeX{} Files
* Internationalization::        Language Support
* Automatic::                   Automatic Customization
* Style Files::                 Writing Your Own Style Support
@end menu

@node Modes and Hooks
@section Modes and Hooks

@AUCTeX{} supports a wide variety of derivatives and extensions of
@TeX{}.  Besides plain @TeX{} those are @LaTeX{}, AMS-@TeX{},
@ConTeXt{}, Texinfo and doc@TeX{}.  For each of them there is a separate
major mode in @AUCTeX{} and each major mode runs @code{text-mode-hook},
@code{TeX-mode-hook} as well as a hook special to the mode in this
order.  (As an exception, Texinfo mode does not run @code{TeX-mode-hook}.)
The following table provides an overview of the respective mode
functions and hooks.

@multitable {Plain @TeX{}} {@code{plain-tex-mode}} {@code{plain-TeX-mode-hook}}
@headitem Type @tab Mode function @tab Hook
@item Plain @TeX{} @tab @code{plain-tex-mode} @tab @code{plain-TeX-mode-hook}
@item @LaTeX{}     @tab @code{latex-mode}     @tab @code{LaTeX-mode-hook}
@item AMS-@TeX{}   @tab @code{ams-tex-mode}   @tab @code{AmS-TeX-mode-hook}
@item @ConTeXt{}   @tab @code{context-mode}   @tab @code{ConTeXt-mode-hook}
@item Texinfo      @tab @code{texinfo-mode}   @tab @code{Texinfo-mode-hook}
@item Doc@TeX{}    @tab @code{doctex-mode}    @tab @code{docTeX-mode-hook}
@end multitable
@findex plain-tex-mode
@vindex plain-TeX-mode-hook
@findex latex-mode
@vindex LaTeX-mode-hook
@findex ams-tex-mode
@vindex AmS-TeX-mode-hook
@findex ConTeXt-mode
@vindex ConTeXt-mode-hook
@findex texinfo-mode
@vindex Texinfo-mode-hook
@findex doctex-mode
@vindex docTeX-mode-hook

If you need to make a customization via a hook which is only relevant
for one of the modes listed above, put it into the respective mode hook,
if it is relevant for any @AUCTeX{} mode, add it to @code{TeX-mode-hook}
and if it is relevant for all text modes, append it to
@code{text-mode-hook}.

Other useful hooks are listed below.

@defvr Variable TeX-after-compilation-finished-hook
Hook which is run after the @TeX{}/@LaTeX{} processor has successfully
finished compiling your document.  (@xref{Processing}, for finding out
how to compile your document.)  Each function in the hook is run with
the compiled output document as its argument.

This is useful for automatically refreshing the viewer after
re-compilation especially when using Emacs viewers such as DocView or
PDF Tools.  The function @code{TeX-revert-document-buffer} can be added
to the hook for this purpose.
@end defvr
@vindex TeX-after-compilation-finished-hook
@findex TeX-revert-document-buffer

@node Multifile
@section Multifile Documents
@cindex Multifile Documents
@cindex Documents
@cindex Documents with multiple files
@cindex Multiple Files
@cindex Many Files
@cindex Including
@cindex \include
@cindex Inputing
@cindex \input
@cindex Master file

You may wish to spread a document over many files (as you are likely to do if
there are multiple authors, or if you have not yet discovered the power
of the outline commands (@pxref{Outline})).  This can be done by having a
``master'' file in which you include the various files with the @TeX{}
macro @samp{\input} or the @LaTeX{} macro @samp{\include}.  These
files may also include other files themselves.  However, to format the
document you must run the commands on the top level master file.

When you, for example, ask @AUCTeX{} to run a command on the master file,
it has no way of knowing the name of the master file.  By default,
it will assume that the current file is the master file.  If you insert
the following in your init file (@file{init.el} or @file{.emacs}), @AUCTeX{} will use a more
advanced algorithm.

@lisp
(setq-default TeX-master nil) ; @r{Query for master file.}
@end lisp

@c FIXME: It doesn't seem that current implementation has this
@c TeX-header-end aware feature.
If @AUCTeX{} finds the line indicating the end of the header in a master
file (@code{TeX-header-end}), it can figure out for itself that this is
a master file.  Otherwise, it will ask for the name of the master file
associated with the buffer.  To avoid asking you again, @AUCTeX{} will
automatically insert the name of the master file as a file variable
(@pxref{File Variables,,,emacs,The Emacs Editor}).  You can also insert
the file variable yourself, by putting the following text at the end of
your files.
@vindex TeX-header-end

@example
%%% Local Variables:
%%% TeX-master: "master"
%%% End:
@end example

You should always set this variable to the name of the top level document.  If
you always use the same name for your top level documents, you can set
@code{TeX-master} in your init file such as @file{init.el} or @file{.emacs}.

@lisp
(setq-default TeX-master "master") ; @r{All master files called @t{"master"}.}
@end lisp

@defopt TeX-master
The master file associated with the current buffer.  If the file being
edited is actually included from another file, then you can tell @AUCTeX{}
the name of the master file by setting this variable.  If there are
multiple levels of nesting, specify the top level file.

If this variable is @code{nil}, @AUCTeX{} will query you for the
name.

If the variable is @code{t}, then @AUCTeX{} will assume the file is a master
file itself.

If the variable is @code{shared}, then @AUCTeX{} will query for the name,
but will not change the file.

If the variable is @code{dwim}, @AUCTeX{} will try to avoid querying by
attempting to ``do what I mean''; and then change the file.
@end defopt

@defopt TeX-one-master
Regular expression matching ordinary @TeX{} files.

You should set this variable to match the name of all files, for which
it is a good idea to append a @code{TeX-master} file variable entry
automatically.  When @AUCTeX{} adds the name of the master file as a
file variable, it does not need to ask next time you edit the file.

If you dislike @AUCTeX{} automatically modifying your files, you can
set this variable to @samp{"<none>"}.  By default, @AUCTeX{} will modify
any file with an extension of @samp{.tex}, @samp{.texi} or @samp{.dtx}.
@end defopt

@deffn Command TeX-master-file-ask
@kindex C-c _
(@kbd{C-c _}) Query for the name of a master file and add the respective
File Variables (@pxref{File Variables,,,emacs,The Emacs Editor}) to the
file for setting this variable permanently.

@AUCTeX{} will not ask for a master file when it encounters existing
files.  This function shall give you the possibility to insert the
variable manually.
@end deffn

@AUCTeX{} keeps track of macros, environments, labels, and style
files that are used in a given document.  For this to work with
multifile documents, @AUCTeX{} has to have a place to put the
information about the files in the document.  This is done by having an
@file{auto} subdirectory placed in the directory where your document is
located.  Each time you save a file, @AUCTeX{} will write information
about the file into the @file{auto} directory.  When you load a file,
@AUCTeX{} will read the information in the @file{auto} directory
about the file you loaded @emph{and the master file specified by
@code{TeX-master}}.  Since the master file (perhaps indirectly) includes
all other files in the document, @AUCTeX{} will get information from
all files in the document.  This means that you will get from each file,
for example, completion for all labels defined anywhere in the document.

@AUCTeX{} will create the @file{auto} directory automatically if
@code{TeX-auto-save} is non-nil.  Without it, the files in the document
will not know anything about each other, except for the name of the
master file.  @xref{Automatic Local}.

@deffn Command TeX-save-document
@kindex C-c C-d
(@kbd{C-c C-d}) Save all buffers known to belong to the current document.
@end deffn

@defopt TeX-save-query
If non-nil, then query the user before saving each file with
@code{TeX-save-document}.
@end defopt


@node Parsing Files
@section Automatic Parsing of @TeX{} Files
@cindex Parsing @TeX{}
@cindex Automatic Parsing
@cindex Tabs
@cindex Tabify
@cindex Untabify

@AUCTeX{} depends heavily on being able to extract information from the
buffers by parsing them.  Since parsing the buffer can be somewhat slow,
the parsing is initially disabled.  You are encouraged to enable them by
adding the following lines to your init file such as @file{init.el} or @file{.emacs}.

@lisp
(setq TeX-parse-self t) ; @r{Enable parse on load.}
(setq TeX-auto-save t) ; @r{Enable parse on save.}
@end lisp

The latter command will make @AUCTeX{} store the parsed information in
an @file{auto} subdirectory in the directory each time the @TeX{} files
are stored, @pxref{Automatic Local}.  If @AUCTeX{} finds the pre-parsed
information when loading a file, it will not need to reparse the buffer.
The information in the @file{auto} directory is also useful for
multifile documents, @pxref{Multifile}, since it allows each file to
access the parsed information from all the other files in the document.
This is done by first reading the information from the master file, and
then recursively the information from each file stored in the master
file.

The variables can also be set on a per file basis, by changing the file
local variables.

@example
%%% Local Variables:
%%% TeX-parse-self: t
%%% TeX-auto-save: t
%%% End:
@end example

Even when you have disabled the automatic parsing, you can force the
generation of style information by pressing @kbd{C-c C-n}.  This is
often the best choice, as you will be able to decide when it is
necessary to reparse the file.

@defopt TeX-parse-self
Parse file after loading it if no style hook is found for it.
@end defopt

@defopt TeX-auto-save
Automatically save style information when saving the buffer.
@end defopt

@deffn Command TeX-normal-mode @var{arg}
@kindex C-c C-n
(@kbd{C-c C-n}) Remove all information about this buffer, and apply the
style hooks again.  Save buffer first including style information.  With
optional argument, also reload the style hooks.
@end deffn

When @AUCTeX{} saves your buffer, it can optionally convert all tabs in
your buffer into spaces.
Tabs confuse @AUCTeX{}'s error message parsing and so should generally be
avoided.  However, tabs are significant in some environments, and so by
default @AUCTeX{} does not remove them.
To convert tabs to spaces when saving a buffer, insert the
following in your init file such as @file{init.el} or @file{.emacs}:

@lisp
(setq TeX-auto-untabify t)
@end lisp

@defopt TeX-auto-untabify
Automatically remove all tabs from a file before saving it.
@end defopt

Instead of disabling the parsing entirely, you can also speed it
significantly up by limiting the information it will search for (and
store) when parsing the buffer.  You can do this by setting the default
values for the buffer local variables @code{TeX-auto-regexp-list} and
@code{TeX-auto-parse-length} in your init file such as @file{init.el} or @file{.emacs}.

@lisp
;; @r{Only parse LaTeX class and package information.}
(setq-default TeX-auto-regexp-list 'LaTeX-auto-minimal-regexp-list)
;; @r{The class and package information is usually near the beginning.}
(setq-default TeX-auto-parse-length 2000)
@end lisp

This example will speed the parsing up significantly, but @AUCTeX{}
will no longer be able to provide completion for labels, macros,
environments, or bibitems specified in the document, nor will it know
what files belong to the document.

These variables can also be specified on a per file basis, by changing
the file local variables.

@example
%%% Local Variables:
%%% TeX-auto-regexp-list: TeX-auto-full-regexp-list
%%% TeX-auto-parse-length: 999999
%%% End:
@end example

@defopt TeX-auto-regexp-list
List of regular expressions used for parsing the current file.
@end defopt

@defopt TeX-auto-parse-length
Maximal length of @TeX{} file that will be parsed.
@end defopt

The pre-specified lists of regexps are defined below.  You can use these
before loading @AUCTeX{} by quoting them, as in the example above.

@defvr Constant TeX-auto-empty-regexp-list
Parse nothing
@end defvr

@defvr Constant LaTeX-auto-minimal-regexp-list
Only parse @LaTeX{} class and packages.
@end defvr

@defvr Constant LaTeX-auto-label-regexp-list
Only parse @LaTeX{} labels.
@end defvr

@defvr Constant LaTeX-auto-index-regexp-list
Only parse @LaTeX{} index and glossary entries.
@end defvr

@defvr Constant LaTeX-auto-class-regexp-list
Only parse macros in @LaTeX{} classes and packages.
@end defvr

@defvr Constant LaTeX-auto-pagestyle-regexp-list
Only parse @LaTeX{} pagestyles.
@end defvr

@defvr Constant LaTeX-auto-counter-regexp-list
Only parse @LaTeX{} counters.
@end defvr

@defvr Constant LaTeX-auto-length-regexp-list
Only parse @LaTeX{} lengths.
@end defvr

@defvr Constant LaTeX-auto-savebox-regexp-list
Only parse @LaTeX{} saveboxes.
@end defvr

@defvr Constant LaTeX-auto-regexp-list
Parse common @LaTeX{} commands.
@end defvr

@defvr Constant plain-TeX-auto-regexp-list
Parse common plain @TeX{} commands.
@end defvr

@defvr Constant TeX-auto-full-regexp-list
Parse all @TeX{} and @LaTeX{} commands that @AUCTeX{} can use.
@end defvr

@node Internationalization
@section Language Support
@cindex Internationalization
@cindex Language Support
@cindex CJK language
@cindex C@TeX{}
@cindex China@TeX{}
@cindex p@TeX{}
@cindex up@TeX{}
@cindex ASCII p@TeX{}
@cindex j@TeX{}
@cindex NTT j@TeX{}
@cindex k@TeX{}
@cindex H@LaTeX{}
@cindex @acronym{CJK}-@LaTeX{}

@TeX{} and Emacs are usable for European (Latin, Cyrillic, Greek) based
languages.  Some @LaTeX{} and EmacsLisp packages are available for easy
typesetting and editing documents in European languages.

@c Some Texinfo macros are not used because they require quite recent
@c texinfo versions (2005-03-05):
@c Second arg of @acronym is available with 4.7, @comma is available in
@c 4.7, @abbr is available in 4.8.
@c -> @abbr{MULE, MULtilingual Enhancement to GNU Emacs}
@c -> @acronym{CJK, Chinese@comma{} Japanese@comma{} and Korean}

All Emacs versions supported by current @AUCTeX{} can handle
@acronym{CJK} (Chinese, Japanese, and Korean) languages by default.

In most cases, special versions of @TeX{} engines are needed for
high-quality typesetting of @acronym{CJK} languages: C@TeX{} and
China@TeX{} for Chinese, ASCII p@TeX{}, up@TeX{} and NTT j@TeX{} for
Japanese, H@LaTeX{} and k@TeX{} for Korean.  They are necessary as well
when you want to typeset documents saved in their domestic encodings
such as @samp{Shift-JIS}.  Currently, @AUCTeX{} offers native support
for p@TeX{}, up@TeX{} and j@TeX{} only.

@c FIXME: We need more information for CTeX, ChinaTeX, KTeX, and HLaTeX.

If you don't need fine tuning in the result with respect to the
typesetting rules of their respective national standards, most unicode
based @TeX{} engines, e.g.@: Lua@TeX{} and Xe@TeX{}, can handle
@acronym{CJK} languages by default if they are encoded in
@acronym{UTF}-8.  The @acronym{CJK}-@LaTeX{} package is provided for
supporting @acronym{CJK} scripts in a standard @LaTeX{} document.

@menu
* European::                    Using @AUCTeX{} with European Languages
* Japanese::                    Using @AUCTeX{} with Japanese
@end menu

@node European
@subsection Using @AUCTeX{} with European Languages
@cindex Europe
@cindex European Characters
@cindex @acronym{ISO} Character set
@cindex @acronym{ISO} 8859 Latin 1
@cindex Latin 1

@subsubsection Typing and Displaying Non-ASCII Characters

First you will need a way to write non-ASCII characters.  You can either
use macros, or teach @TeX{} about the @acronym{ISO} character sets.  I prefer the
latter, it has the advantage that the usual standard emacs word
movement and case change commands will work.

Recommended encoding for @LaTeX{} document is @acronym{UTF}-8.  Recent
@LaTeX{}2e has native support for @acronym{UTF}-8.  If your @LaTeX{}2e is
not recent enough, just add @samp{\usepackage[utf8]@{inputenc@}}.

You can still use @acronym{ISO} 8859 Latin 1 encoding with
@samp{\usepackage[latin1]@{inputenc@}}.

To be able to display non-ASCII characters you will need an appropriate
font.  All Emacs versions supported by current @AUCTeX{} can display 8-bit
characters, provided that suitable fonts are installed.

@c FIXME: These are considered as kind of obsolete, aren't they?
A compromise is to use an European character set when editing the file,
and convert to @TeX{} macros when reading and writing the files.

@table @file
@item iso-cvt.el
@cindex @file{iso-cvt.el}
Much like @file{iso-tex.el} but is bundled with Emacs 19.23 and later.

@item X-Symbol
@cindex X-Symbol
a much more complete package for Emacs that can also handle a lot of
mathematical characters and input methods.
@end table

@subsubsection Style Files for Different Languages

@cindex ispell
@AUCTeX{} supports style files for several languages.  Each style file
may modify @AUCTeX{} to better support the language, and will run
a language specific hook that will allow you to for example change
ispell dictionary, or run code to change the keyboard remapping.  The
following will for example choose a Danish dictionary for documents
including @samp{\usepackage[danish]@{babel@}}.
This requires parsing to be enabled, @pxref{Parsing Files}.

@lisp
(add-hook 'TeX-language-dk-hook
          (lambda () (ispell-change-dictionary "danish")))
@end lisp

The following style files are recognized:

@c In alphabetic order of the hooks:
@vindex TeX-language-bg-hook
@vindex TeX-language-cz-hook
@vindex TeX-language-dk-hook
@vindex TeX-language-en-hook
@vindex TeX-language-nl-hook
@vindex TeX-language-de-hook
@vindex TeX-language-it-hook
@vindex TeX-language-is-hook
@vindex TeX-language-pl-hook
@vindex TeX-language-pt-br-hook
@vindex TeX-language-pt-hook
@vindex TeX-language-sk-hook
@vindex TeX-language-sv-hook
@cindex Brazilian Portuguese
@cindex Bulgarian
@cindex Czech
@cindex Italian
@cindex Danish
@cindex Dutch
@cindex English
@cindex German
@cindex Polish
@cindex Portuguese
@cindex Slovak
@cindex Swedish
@table @file
@item brazilian
@itemx brazil
Runs style hook @code{TeX-language-pt-br-hook}.  Gives @samp{"} word
syntax, makes the @key{"} key inserts @samp{``} or @samp{''} depending on
context.  Typing @key{"} twice will insert a literal @samp{"}.  Typing
@key{-} twice will insert @samp{"=}, three times @samp{--}.

@item bulgarian
Runs style hook @code{TeX-language-bg-hook}.  Gives @samp{"} word syntax,
makes the @key{"} key insert a literal @samp{"}.  Typing @key{"} twice
will insert @samp{"`} or @samp{"'} depending on context.  Typing @key{-}
twice will insert @samp{"=}, three times @samp{--}.

@item czech
Runs style hook @code{TeX-language-cz-hook}.  Pressing @key{"} will
insert @samp{\uv@{} and @samp{@}} depending on context.

@c FIXME: Is the difference between dk and danish really intented?
@item danish
Runs style hook @code{TeX-language-dk-hook}.  Pressing @key{"} will
insert @samp{"`} and @samp{"'} depending on context.  Typing @key{-}
twice will insert @samp{"=}, i.e.@: a hyphen string allowing hyphenation
in the composing words.
@c dk.sty seems to be obsolete, so we don't want to encourage using it.
@c @item dk
@c Runs style hook @code{TeX-language-dk-hook}.

@item dutch
Runs style hook @code{TeX-language-nl-hook}.

@item english
@itemx australian
@itemx canadian
@itemx newzealand
Runs style hook @code{TeX-language-en-hook}.

@item frenchb
@itemx francais
Runs style hook @code{TeX-language-fr-hook}.  Pressing @key{"} will
insert @samp{\og} and @samp{\fg} depending on context.  Note that the
language name for customizing @code{TeX-quote-language-alist} is
@samp{french}.

@item german
@itemx ngerman
Runs style hook @code{TeX-language-de-hook}.  Gives @samp{"} word
syntax, makes the @key{"} key insert a literal @samp{"}.  Pressing the
key twice will give you opening or closing German quotes (@samp{"`} or
@samp{"'}).  Typing @key{-} twice will insert @samp{"=}, three times
@samp{--}.

@item icelandic
Runs style hook @code{TeX-language-is-hook}.  Gives @samp{"} word syntax,
makes the @key{"} key insert a literal @samp{"}.  Typing @key{"} twice
will insert @samp{"`} or @samp{"'} depending on context.  Typing @key{-}
twice will insert @samp{"=}, three times @samp{--}.

@item italian
Runs style hook @code{TeX-language-it-hook}.  Pressing @key{"} will
insert @samp{"<} and @samp{">} depending on context.

@item polish
Runs style hook @code{TeX-language-pl-hook}.  Gives @samp{"} word syntax
and makes the @key{"} key insert a literal @samp{"}.  Pressing @key{"}
twice will insert @samp{"`} or @samp{"'} depending on context.

@item polski
Runs style hook @code{TeX-language-pl-hook}.  Makes the @key{"} key
insert a literal @samp{"}.  Pressing @key{"} twice will insert @samp{,,}
or @samp{''} depending on context.

@item portuguese
@itemx portuges
Runs style hook @code{TeX-language-pt-hook}.  Gives @samp{"} word syntax,
makes the @key{"} key inserts @samp{"<} or @samp{">} depending on context.
Typing @key{"} twice will insert a literal @samp{"}.  Typing @key{-} twice
will insert @samp{"=}, three times @samp{--}.  Note that the language name
for customizing @code{TeX-quote-language-alist} is @samp{portuguese}.

@item slovak
Runs style hook @code{TeX-language-sk-hook}.  Pressing @key{"} will
insert @samp{\uv@{} and @samp{@}} depending on context.

@item swedish
Runs style hook @code{TeX-language-sv-hook}.  Pressing @key{"} will
insert @samp{''}.  Typing @key{-} twice will insert @samp{"=}, three
times @samp{--}.
@end table

Replacement of language-specific hyphen strings like @samp{"=} with
dashes does not require to type @key{-} three times in a row.  You can
put point after the hypen string anytime and trigger the replacement by
typing @key{-}.

In case you are not satisfied with the suggested behavior of quote and
hyphen insertion you can change it by customizing the variables
@code{TeX-quote-language-alist} and
@code{LaTeX-babel-hyphen-language-alist} respectively.

@defopt TeX-quote-language-alist
Used for overriding the default language-specific quote insertion
behavior.  This is an alist where each element is a list consisting of
four items.  The first item is the name of the language in concern as a
string.  See the list of supported languages above.  The second item is
the opening quotation mark.  The third item is the closing quotation
mark.  Opening and closing quotation marks can be specified directly as
strings or as functions returning a string.  The fourth item is a
boolean controlling quote insertion.  It should be non-nil if if the
special quotes should only be used after inserting a literal @samp{"}
character first, i.e.@: on second key press.
@end defopt

@defopt LaTeX-babel-hyphen-language-alist
Used for overriding the behavior of hyphen insertion for specific
languages.  Every element in this alist is a list of three items.  The
first item should specify the affected language as a string.  The second
item denotes the hyphen string to be used as a string.  The third item,
a boolean, controls the behavior of hyphen insertion and should be
non-nil if the special hyphen should be inserted after inserting a
literal @samp{-} character, i.e.@: on second key press.
@end defopt

The defaults of hyphen insertion are defined by the variables
@code{LaTeX-babel-hyphen} and @code{LaTeX-babel-hyphen-after-hyphen}
respectively.

@defopt LaTeX-babel-hyphen
String to be used when typing @key{-}.  This usually is a hyphen
alternative or hyphenation aid provided by @samp{babel} and the related
language style files, like @samp{"=}, @samp{"~} or @samp{"-}.

Set it to an empty string or nil in order to disable language-specific
hyphen insertion.
@end defopt

@defopt LaTeX-babel-hyphen-after-hyphen
Control insertion of hyphen strings.  If non-nil insert normal hyphen on
first key press and swap it with the language-specific hyphen string
specified in the variable @code{LaTeX-babel-hyphen} on second key press.
If nil do it the other way round.
@end defopt

@node Japanese
@subsection Using @AUCTeX{} with Japanese @TeX{}
@cindex Japan
@cindex Japanese
@cindex Nippon
@cindex NTT j@TeX{}
@cindex j@TeX{}
@cindex j@LaTeX{}
@cindex ASCII p@TeX{}
@cindex p@TeX{}
@cindex p@LaTeX{}
@cindex up@TeX{}
@cindex up@LaTeX{}
@cindex @file{tex-jp.el}
@vindex TeX-default-mode
@vindex TeX-parse-self
@vindex TeX-engine
@vindex TeX-engine-alist
@vindex japanese-TeX-mode
@findex japanese-plain-tex-mode
@findex japanese-latex-mode

To write Japanese text with @AUCTeX{}, you need the versions of
@TeX{} and Emacs that support Japanese.  @AUCTeX{} supports three
Japanese @TeX{} engines by default: NTT j@TeX{}, ASCII p@TeX{} and
up@TeX{}.

Activate @code{japanese-plain-tex-mode} or @code{japanese-latex-mode} to
use the Japanese @TeX{} engines.  If it doesn't work, send mail to
Masayuki Ataka @email{masayuki.ataka@@gmail.com} or Ikumi Keita
@email{ikumikeita@@jcom.home.ne.jp}, who currently concern with stuff
related to Japanese in @AUCTeX{}.  None of the primary @AUCTeX{}
maintainers understand Japanese, so they cannot help you.

It is recommended to enable @code{TeX-parse-self} for typical Japanese
@LaTeX{} users.  When enabled, @code{japanese-latex-mode} selects the
suitable Japanese @TeX{} engine automatically based on the class file
name (such as @code{jbook}, @code{jsarticle} and @code{tjreport}) and
its option.  @xref{Parsing Files}.

It is important to select the suitable Japanese @TeX{} engine because
the selected engine determines the command name such as @command{platex}
and @command{uptex} to typeset the document.  If you find that wrong
command is used, check the value of @code{TeX-engine} on that buffer.
If the value does not suit the current document, change the value by the
@samp{TeXing Options} submenu below the @samp{Command} menu.
@xref{Processor Options}.

To make the selected engine to persist across Emacs sessions, there are
two ways from which you can choose one according to your needs:

@enumerate
@item
If you use a specific engine (almost) exclusively, customize the option
@code{japanese-TeX-engine-default}.

@defopt japanese-TeX-engine-default
The default @code{TeX-engine} in Japanese @TeX{} mode.

The default value is @samp{ptex}.
@end defopt
@item
If you want to set the engine on a per file basis, use the file local
variables to set @code{TeX-engine}.

Here is a sample code to set @code{TeX-engine} to @samp{uptex}:

@example
%%% Local Variables:
%%% mode: japanese-latex
%%% TeX-engine: uptex
%%% End:
@end example
@end enumerate

In the both cases above, the valid value is one of @samp{ptex},
@samp{jtex} and @samp{uptex}.

You can override the command names associated with the above three
engines or define your own engine by customizing
@code{TeX-engine-alist}.  @xref{Processor Options}.

It is sometimes necessary to use an engine which differs from the one
@AUCTeX{} selects automatically.  For example, even when you want to use
@code{j-article} document class deliberately with ASCII p@LaTeX{},
@AUCTeX{} selects NTT j@LaTeX{} command if @code{TeX-parse-self} is
enabled, because @code{j-article} originally belongs to NTT j@LaTeX{}.
In such cases, use the file local variable method above to select the
engine you intend to use.

If you usually use @AUCTeX{} in Japanese, setting the following
variables is useful.

@defopt TeX-default-mode
Mode to enter for a new file when it cannot be determined whether the
file is plain @TeX{} or @LaTeX{} or what.

If you want to enter Japanese @LaTeX{} mode whenever this may happen,
set the variable like this:
@lisp
(setq TeX-default-mode 'japanese-latex-mode)
@end lisp
@end defopt

@defopt japanese-LaTeX-default-style
The default style/class when creating a new Japanese @LaTeX{} document.

The default value is @samp{"jarticle"}.
@end defopt

It is recommended also for Japanese users to customize the option
@code{TeX-PDF-from-DVI} to @samp{"Dvipdfmx"}.  @xref{Processor Options}.

There are three customize options with regard to the encoding of
Japanese text.

@defopt japanese-TeX-use-kanji-opt-flag
If non-nil, @AUCTeX{} adds @option{-kanji} option to the typesetting
command when @code{TeX-engine} is @samp{ptex}.
@end defopt

Usually @AUCTeX{} guesses the right coding systems for input to and
output from the Japanese @TeX{} process, but you can override them by
the following two customize options.

@defopt TeX-japanese-process-input-coding-system
If non-nil, used for encoding input to Japanese @TeX{} process.
When @code{nil}, @AUCTeX{} tries to choose suitable coding system.
@end defopt

@defopt TeX-japanese-process-output-coding-system
If non-nil, used for decoding output from Japanese @TeX{} process.
When @code{nil}, @AUCTeX{} tries to choose suitable coding system.
@end defopt

The former customize options @code{japanese-TeX-command-default},
@code{japanese-LaTeX-command-default} and
@code{japanese-TeX-command-list} are removed from @AUCTeX{}.  Use
@code{japanese-TeX-engine-default} instead.  If you need to customize
the executable file name such as @samp{"latex"}, the options for them,
or both, customize @code{TeX-engine-alist}.

The following two additional font commands are available in
@LaTeX{} mode buffer.

@table @kbd
@item C-c C-f g
@kindex C-c C-f g
@cindex @code{\textgt}
@cindex @code{\mathgt}
Insert @b{gothic font} command @samp{\textgt@{@point{}@}} or
@samp{\mathgt@{@point{}@}} depending on the context.

@item C-c C-f m
@kindex C-c C-f m
@cindex @code{\textmc}
@cindex @code{\mathmc}
Insert mincho font command @samp{\textmc@{@point{}@}} or
@samp{\mathmc@{@point{}@}} depending on the context.

@end table

Although they are meaningful only with @samp{ptex} and @samp{uptex}
engines, it won't matter in buffers with other engines.

See @file{tex-jp.el} for more information.

@node Automatic
@section Automatic Customization
@cindex Automatic Customization
@cindex Extracting @TeX{} symbols
@cindex Automatic
@cindex @file{auto} directories.
@cindex Parsing @TeX{}
@cindex @TeX{} parsing
@cindex Generating symbols

Since @AUCTeX{} is so highly customizable, it makes sense that it is able
to customize itself.  The automatic customization consists of scanning
@TeX{} files and extracting symbols, environments, and things like that.

The automatic customization is done on three different levels.  The
global level is the level shared by all users at your site, and consists
of scanning the standard @TeX{} style files, and any extra styles added
locally for all users on the site.  The private level deals with those
style files you have written for your own use, and use in different
documents.  You may have a @file{~/lib/TeX/} directory where you store
useful style files for your own use.  The local level is for a specific
directory, and deals with writing customization for the files for your
normal @TeX{} documents.

If compared with the environment variable @env{TEXINPUTS}, the
global level corresponds to the directories built into @TeX{}.  The
private level corresponds to the directories you add yourself, except for
@file{.}, which is the local level.

@menu
* Automatic Global::            Automatic Customization for the Site
* Automatic Private::           Automatic Customization for a User
* Automatic Local::             Automatic Customization for a Directory
@end menu

By default @AUCTeX{} will search for customization files in all the
global, private, and local style directories, but you can also set the
path directly.  This is useful if you for example want to add another
person's style hooks to your path.  Please note that all matching files
found in @code{TeX-style-path} are loaded, and all hooks defined in the
files will be executed.

@defopt TeX-style-path
List of directories to search for @AUCTeX{} style files.
@end defopt

By default, when @AUCTeX{} searches a directory for files, it will
recursively search through subdirectories.

@defopt TeX-file-recurse
Whether to search @TeX{} directories recursively: nil means do not
recurse, a positive integer means go that far deep in the directory
hierarchy, t means recurse indefinitely.
@end defopt

By default, @AUCTeX{} will ignore files named @file{.}, @file{..},
@file{SCCS}, @file{RCS}, and @file{CVS}.

@defopt TeX-ignore-file
Regular expression matching file names to ignore.

These files or directories will not be considered when searching for
@TeX{} files in a directory.
@end defopt

@node Automatic Global
@subsection Automatic Customization for the Site
@cindex Global style hook directory
@cindex Global macro directory
@cindex Site macro directory
@cindex Global @TeX{} macro directory
@cindex Site @TeX{} macro directory
@cindex Global directories
@cindex Site information

Assuming that the automatic customization at the global level was done
when @AUCTeX{} was installed, your choice is now: will you use it?  If
you use it, you will benefit by having access to all the symbols and
environments available for completion purposes.  The drawback is slower
load time when you edit a new file and perhaps too many confusing
symbols when you try to do a completion.

You can disable the automatic generated global style hooks by setting
the variable @code{TeX-auto-global} to nil.

@defopt TeX-macro-global
Directories containing the site's @TeX{} style files.
@end defopt

@defopt TeX-style-global
Directory containing hand generated @TeX{} information.

These correspond to @TeX{} macros shared by all users of a site.
@end defopt

@defopt TeX-auto-global
Directory containing automatically generated information.

For storing automatic extracted information about the @TeX{} macros
shared by all users of a site.
@end defopt

@node Automatic Private
@subsection Automatic Customization for a User
@cindex Private style hook directory
@cindex Private macro directory
@cindex Personal macro directory
@cindex Private @TeX{} macro directory
@cindex Personal @TeX{} macro directory
@cindex Private directories
@cindex Personal information

You should specify where you store your private @TeX{} macros, so
@AUCTeX{} can extract their information.  The extracted information will
go to the directories listed in @code{TeX-auto-private}

Use @kbd{M-x TeX-auto-generate @key{RET}} to extract the information.

@defopt TeX-macro-private
Directories where you store your personal @TeX{} macros.  The value
defaults to the directories listed in the @env{TEXINPUTS} and
@env{BIBINPUTS} environment variables or to the respective directories
in @code{$TEXMFHOME} of @command{kpsewhich} setting if no results can be obtained from the environment
variables.
@end defopt

@defopt TeX-auto-private
List of directories containing automatically generated @AUCTeX{} style
files.  These correspond to the personal @TeX{} macros.
@end defopt

@deffn Command TeX-auto-generate @var{tex} @var{auto}
(@kbd{M-x TeX-auto-generate @key{RET}}) Generate style hook for
@var{tex} and store it in @var{auto}.  If @var{tex} is a directory,
generate style hooks for all files in the directory.
@end deffn

@defopt TeX-style-private
List of directories containing hand generated @AUCTeX{} style files.
These correspond to the personal @TeX{} macros.
@end defopt

@node Automatic Local
@subsection Automatic Customization for a Directory
@cindex Local style hooks
@cindex Updating style hooks
@cindex Automatic updating style hooks
@cindex Local style hooks
@cindex Local style directory

@AUCTeX{} can update the style information about a file each time you
save it, and it will do this if the directory @code{TeX-auto-local}
exists.  @code{TeX-auto-local} is by default set to @samp{"auto"}, so
simply creating an @file{auto} directory will enable automatic saving of
style information.

The advantage of doing this is that macros, labels, etc.@: defined in any
file in a multifile document will be known in all the files in the
document.  The disadvantage is that saving will be slower.  To disable,
set @code{TeX-auto-local} to nil.

@defopt TeX-style-local
Directory containing hand generated @TeX{} information.

These correspond to @TeX{} macros found in the current directory.
@end defopt

@defopt TeX-auto-local
Directory containing automatically generated @TeX{} information.

These correspond to @TeX{} macros found in the current directory.
@end defopt

@node Style Files
@section Writing Your Own Style Support
@cindex Style files
@cindex Style hooks
@cindex @file{style}

@xref{Automatic}, for a discussion about automatically generated global,
private, and local style files.  The hand generated style files are
equivalent, except that they by default are found in @file{style}
directories instead of @file{auto} directories.

@menu
* Simple Style::                A Simple Style File
* Adding Macros::               Adding Support for Macros
* Adding Environments::         Adding Support for Environments
* Adding Other::                Adding or Examining Other Information
* Hacking the Parser::          Automatic Extraction of New Things
@end menu

If you write some useful support for a public @TeX{} style file, please
send it to us.

@node Simple Style
@subsection A Simple Style File
@cindex @file{book.el}
@cindex Sample style file
@cindex Style file
@cindex Example of a style file.
@cindex Style hook
@cindex Adding a style hook

Here is a simple example of a style file.

@lisp
;;; book.el - Special code for book style.

(TeX-add-style-hook
 "book"
 (lambda () 
   (LaTeX-largest-level-set "part"))
 TeX-dialect)
@end lisp

The example is from the @AUCTeX{} sources and is loaded for any @LaTeX{}
document using the book document class (or style before @LaTeX{}2e).
(Note that the above code is much simplified for explanatory purpose.)
The file specifies that the largest kind of section in such a document
is @samp{part}.  The interesting thing to notice is that the style file
defines an (anonymous) function, and adds it to the list of loaded style
hooks by calling @code{TeX-add-style-hook}.

The first time the user indirectly tries to access some style-specific
information, such as the largest sectioning command available, the style
hooks for all files directly or indirectly read by the current document
are executed.  The actual files will only be evaluated once, but the
hooks will be called for each buffer using the style file.

Note that the basename of the style file and the name of the style hook
should usually be identical.

@defun TeX-add-style-hook @var{style} @var{hook} &optional @var{dialect-expr}
Add @var{hook} to the list of functions to run when we use the @TeX{}
file @var{style} and the current dialect is one in the set derived from
@var{dialect-expr}.  When @var{dialect-expr} is omitted, then @var{hook}
is allowed to be run whatever the current dialect is.

@var{dialect-expr} may be one of:

@itemize
@item
A symbol indicating a singleton containing one basic @TeX{} dialect,
this symbol shall be selected among:
@table @code
@item :latex
For all files in @LaTeX{} mode, or any mode derived thereof.
@item :bibtex
For all files in Bib@TeX{} mode, or any mode derived thereof.
@item :texinfo
For all files in Texinfo mode.
@item :plain-tex
For all files in plain-@TeX{} mode, or any mode derived thereof.
@item :context
For all files in @ConTeXt{} mode.
@item :classopt
For class options of @LaTeX{} document.  This is provided as
pseudo-dialect for style hooks associated with class options.
@end table
@item
A logical expression like:
@table @code
@item (or @var{dialect-expression1} @dots{} @var{dialect-expression_@var{n}})
For union of the sets of dialects corresponding to  @var{dialect-expression1}
through @var{dialect-expression_@var{n}}
@item (and @var{dialect-expression1} @dots{} @var{dialect-expression_@var{n}})
For intersection of the sets of dialects corresponding to
@var{dialect-expression1} through @var{dialect-expression_@var{n}}
@item (nor @var{dialect-expression1} @dots{} @var{dialect-expression_@var{n}})
For complement of the union sets of dialects corresponding to
@var{dialect-expression1} through @var{dialect-expression_@var{n}}
relatively to the set of all supported dialects
@item (not @var{dialect-expr})
For complement set of dialect corresponding to @var{dialect-expr}
relatively to the set of all supported dialects
@end table
@end itemize

@end defun

In case of adding a style hook for @LaTeX{}, when calling function
@code{TeX-add-style-hook} it is thought more futureproof for argument
@var{dialect-expr} to pass constant @code{TeX-dialect} currently
defined to @code{:latex}, rather than passing @code{:latex} directly.

@defvr Constant TeX-dialect
Default dialect for use with function @code{TeX-add-style-hook} for
argument @var{dialect-expr} when the hook is to be run only on @LaTeX{}
file, or any mode derived thereof.
@end defvr


@node Adding Macros
@subsection Adding Support for Macros
@cindex Adding macros
@cindex Macros, adding
@cindex Defining macros in style hooks

The most common thing to define in a style hook is new symbols (@TeX{}
macros).  Most likely along with a description of the arguments to the
function, since the symbol itself can be defined automatically.

Here are a few examples from @file{latex.el}.

@lisp
(TeX-add-style-hook
 "latex"
 (lambda ()
   (TeX-add-symbols
    '("arabic" TeX-arg-counter)
    '("label" TeX-arg-define-label)
    '("ref" TeX-arg-ref)
    '("newcommand" TeX-arg-define-macro [ "Number of arguments" ] t)
    '("newtheorem" TeX-arg-define-environment
      [ TeX-arg-environment "Numbered like" ]
      t [ TeX-arg-counter "Within counter" ]))))
@end lisp

@defun TeX-add-symbols @var{symbol} @dots{}
Add each @var{symbol} to the list of known symbols.
@end defun

Each argument to @code{TeX-add-symbols} is a list describing one symbol.
The head of the list is the name of the symbol, the remaining elements
describe each argument.

If there are no additional elements, the symbol will be inserted with
point inside braces.  Otherwise, each argument of this function should
match an argument of the @TeX{} macro.  What is done depends on the argument
type.

If a macro is defined multiple times, @AUCTeX{} will choose the one with
the longest definition (i.e.@: the one with the most arguments).

Thus, to overwrite
@example
        '("tref" 1) ; @r{one argument}
@end example
you can specify
@example
        '("tref" TeX-arg-ref ignore) ; @r{two arguments}
@end example

@code{ignore} is a function that does not do anything, so when you
insert a @samp{tref} you will be prompted for a label and no more.

You can use the following types of specifiers for arguments:

@table @code
@item string
Use the string as a prompt to prompt for the argument.

@item number
Insert that many braces, leave point inside the first.  0 and -1 are
special.  0 means that no braces are inserted.  -1 means that braces are
inserted around the macro and an active region (e.g.@: @samp{@{\tiny
foo@}}).  If there is no active region, no braces are inserted.

@item nil
Insert empty braces.

@item t
Insert empty braces, leave point between the braces.

@item other symbols
Call the symbol as a function.  You can define your
own hook, or use one of the predefined argument hooks.

@item list
If the car is a string, insert it as a prompt and the next
element as initial input.  Otherwise, call the car of the list with
the remaining elements as arguments.

@item vector
Optional argument.  If it has more than one element, parse it
as a list, otherwise parse the only element as above.  Use square
brackets instead of curly braces, and is not inserted on empty user
input.
@end table

A lot of argument hooks have already been defined.  The first argument to
all hooks is a flag indicating if it is an optional argument.  It is up
to the hook to determine what to do with the remaining arguments, if
any.  Typically the next argument is used to overwrite the default
prompt.

@ftable @code
@item TeX-arg-conditional
Implements if @var{expr} @var{then} @var{else}.  If @var{expr} evaluates to true, parse @var{then} as an
argument list, else parse @var{else} as an argument list.

@item TeX-arg-literal
Insert its arguments into the buffer.  Used for specifying extra syntax
for a macro.

@item TeX-arg-free
Parse its arguments but use no braces when they are inserted.

@item TeX-arg-eval
Evaluate arguments and insert the result in the buffer.

@item TeX-arg-label
Prompt for a label completing with known labels.  If Ref@TeX{} is
active, prompt for the reference format.

@item TeX-arg-ref
Prompt for a label completing with known labels.  If Ref@TeX{} is
active, do not prompt for the reference format.  Usually, reference
macros should use this function instead of @code{TeX-arg-label}.

@item TeX-arg-index-tag
Prompt for an index tag.  This is the name of an index, not the entry.

@item TeX-arg-index
Prompt for an index entry completing with known entries.

@item TeX-arg-length
Prompt for a @LaTeX{} length completing with known lengths.

@item TeX-arg-macro
Prompt for a @TeX{} macro with completion.

@item TeX-arg-date
@vindex TeX-date-format
Prompt for a date, defaulting to the current date.  The format of the
date is specified by the @code{TeX-date-format} option.  If you want to
change the format when the @samp{babel} package is loaded with a
specific language, set @code{TeX-date-format} inside the appropriate
language hook (for details @pxref{European}).

@item TeX-arg-version
Prompt for the version of a file, using as initial input the current
date.

@item TeX-arg-environment
Prompt for a @LaTeX{} environment with completion.

@item TeX-arg-cite
@vindex TeX-arg-cite-note-p
Prompt for a Bib@TeX{} citation.  If the variable
@code{TeX-arg-cite-note-p} is non-nil, ask also for optional note in citations.

@item TeX-arg-counter
Prompt for a @LaTeX{} counter completing with known counters.

@item TeX-arg-savebox
Prompt for a @LaTeX{} savebox completing with known saveboxes.

@item TeX-arg-file
Prompt for a filename in the current directory, and use it with the
extension.

@item TeX-arg-file-name
Prompt for a filename and use as initial input the name of the file
being visited in the current buffer, with extension.

@item TeX-arg-file-name-sans-extension
Prompt for a filename and use as initial input the name of the file
being visited in the current buffer, without extension.

@item TeX-arg-input-file
@vindex TeX-arg-input-file-search
Prompt for the name of an input file in @TeX{}'s search path, and use it
without the extension.  Run the style hooks for the file.  (Note that
the behavior (type of prompt and inserted file name) of the function can
be controlled by the variable @code{TeX-arg-input-file-search}.)

@item TeX-arg-define-label
Prompt for a label completing with known labels.  Add label to list of
defined labels.

@item TeX-arg-define-length
Prompt for a @LaTeX{} length completing with known lengths.  Add length
to list of defined lengths.

@item TeX-arg-define-macro
Prompt for a @TeX{} macro with completion.  Add macro to list of defined
macros.

@item TeX-arg-define-environment
Prompt for a @LaTeX{} environment with completion.  Add environment to
list of defined environments.

@item TeX-arg-define-cite
Prompt for a Bib@TeX{} citation.

@item TeX-arg-define-counter
Prompt for a @LaTeX{} counter.

@item TeX-arg-define-savebox
Prompt for a @LaTeX{} savebox.

@item TeX-arg-document
@vindex LaTeX-default-style
@vindex LaTeX-default-options
@vindex TeX-arg-input-file-search
@vindex LaTeX-style-list
Prompt for a @LaTeX{} document class, using @code{LaTeX-default-style}
as default value and @code{LaTeX-default-options} as default list of
options.  If the variable @code{TeX-arg-input-file-search} is t, you
will be able to complete with all @LaTeX{} classes available on your
system, otherwise classes listed in the variable @code{LaTeX-style-list}
will be used for completion.  It is also provided completion for options
of many common classes.

@item LaTeX-arg-usepackage
@vindex TeX-arg-input-file-search
Prompt for @LaTeX{} packages.  If the variable
@code{TeX-arg-input-file-search} is t, you will be able to complete with
all @LaTeX{} packages available on your system.  It is also provided
completion for options of many common packages.

@item TeX-arg-bibstyle
Prompt for a Bib@TeX{} style file completing with all style available on
your system.

@item TeX-arg-bibliography
Prompt for Bib@TeX{} database files completing with all databases available
on your system.

@item TeX-arg-corner
Prompt for a @LaTeX{} side or corner position with completion.

@item TeX-arg-lr
Prompt for a @LaTeX{} side with completion.

@item TeX-arg-tb
Prompt for a @LaTeX{} side with completion.

@item TeX-arg-pagestyle
Prompt for a @LaTeX{} pagestyle with completion.

@item TeX-arg-verb
Prompt for delimiter and text.

@item TeX-arg-verb-delim-or-brace
Prompt for delimiter and text.  This function is similar to
@code{TeX-arg-verb}, but is intended for macros which take their
argument enclosed in delimiters or in braces.

@item TeX-arg-pair
Insert a pair of numbers, use arguments for prompt.  The numbers are
surrounded by parentheses and separated with a comma.

@item TeX-arg-size
Insert width and height as a pair.  No arguments.

@item TeX-arg-coordinate
Insert x and y coordinates as a pair.  No arguments.

@item LaTeX-arg-author
@vindex LaTeX-default-author
Prompt for document author, using @code{LaTeX-default-author} as initial
input.

@item TeX-read-key-val
Prompt for a @samp{key=value} list of options and return them.

@item TeX-arg-key-val
Prompt for a @samp{key=value} list of options and insert it as a @TeX{} macro
argument.
@end ftable

If you add new hooks, you can assume that point is placed directly after
the previous argument, or after the macro name if this is the first
argument.  Please leave point located after the argument you are
inserting.  If you want point to be located somewhere else after all
hooks have been processed, set the value of @code{TeX-exit-mark}.  It
will point nowhere, until the argument hook sets it.

Some packages provide macros that are rarely useful to non-expert users.
Those should be marked as expert macros using
@code{TeX-declare-expert-macros}.

@defun TeX-declare-expert-macros @var{style} @var{macros}...
Declare @var{macros} as expert macros of @var{style}.

Expert macros are completed depending on @code{TeX-complete-expert-commands}.
@end defun


@node Adding Environments
@subsection Adding Support for Environments
@cindex Adding environments
@cindex Environments, adding
@cindex Defining environments in style hooks

Adding support for environments is very much like adding support for
@TeX{} macros, except that each environment normally only takes one
argument, an environment hook.  The example is again a short version of
@file{latex.el}.

@lisp
(TeX-add-style-hook
 "latex"
 (lambda ()
   (LaTeX-add-environments
    '("document" LaTeX-env-document)
    '("enumerate" LaTeX-env-item)
    '("itemize" LaTeX-env-item)
    '("list" LaTeX-env-list))))
@end lisp

It is completely up to the environment hook to insert the environment,
but the function @code{LaTeX-insert-environment} may be of some help.
The hook will be called with the name of the environment as its first
argument, and extra arguments can be provided by adding them to a list
after the hook.

For simple environments with arguments, for example defined with
@samp{\newenvironment}, you can make @AUCTeX{} prompt for the arguments
by giving the prompt strings in the call to
@code{LaTeX-add-environments}.  The fact that an argument is optional
can be indicated by wrapping the prompt string in a vector.

For example, if you have defined a @code{loop} environment with the
three arguments @var{from}, @var{to}, and @var{step}, you can add
support for them in a style file.

@example
%% loop.sty

\newenvironment@{loop@}[3]@{...@}@{...@}
@end example

@lisp
;; loop.el

(TeX-add-style-hook
 "loop"
 (lambda ()
   (LaTeX-add-environments
    '("loop" "From" "To" "Step"))))
@end lisp

If an environment is defined multiple times, @AUCTeX{} will choose the
one with the longest definition.  Thus, if you have an enumerate style
file, and want it to replace the standard @LaTeX{} enumerate hook above,
you could define an @file{enumerate.el} file as follows, and place it in
the appropriate style directory.

@lisp
(TeX-add-style-hook
 "latex"
 (lambda ()
   (LaTeX-add-environments
    '("enumerate" LaTeX-env-enumerate foo))))

(defun LaTeX-env-enumerate (environment &optional _ignore) ...)
@end lisp

The symbol @code{foo} will be passed to @code{LaTeX-env-enumerate} as
the second argument, but since we only added it to overwrite the
definition in @file{latex.el} it is just ignored.

@defun LaTeX-add-environments @var{env} @dots{}
Add each @var{env} to list of loaded environments.
@end defun

@defun LaTeX-insert-environment @var{env} [ @var{extra} ]
Insert environment of type @var{env}, with optional argument @var{extra}.
@end defun

Following is a list of available hooks for
@code{LaTeX-add-environments}:

@ftable @code
@item LaTeX-env-item
Insert the given environment and the first item.

@item LaTeX-env-figure
Insert the given figure-like environment with a caption and a label.

@item LaTeX-env-array
Insert the given array-like environment with position and column
specifications.

@item LaTeX-env-label
Insert the given environment with a label.

@item LaTeX-env-list
Insert the given list-like environment, a specifier for the label and
the first item.

@item LaTeX-env-minipage
Insert the given minipage-like environment with position and width
specifications.

@item LaTeX-env-tabular*
Insert the given tabular*-like environment with width, position and
column specifications.

@item LaTeX-env-picture
Insert the given environment with width and height specifications.

@item LaTeX-env-bib
Insert the given environment with a label for a bibitem.

@item LaTeX-env-contents
Insert the given environment with a filename as its argument.

@item LaTeX-env-args
Insert the given environment with arguments.  You can use this as a hook
in case you want to specify multiple complex arguments just like in
elements of @code{TeX-add-symbols}.  This is most useful if the
specification of arguments to be prompted for with strings and strings
wrapped in a vector as described above is too limited.

Here is an example from @file{listings.el} which calls a function with
one argument in order to prompt for a @samp{key=value} list to be inserted as
an optional argument of the @samp{lstlisting} environment:

@lisp
(LaTeX-add-environments
 '("lstlisting" LaTeX-env-args
   [TeX-arg-key-val LaTeX-listings-key-val-options]))
@end lisp
@end ftable

Some packages provide environments that are rarely useful to non-expert
users.  Those should be marked as expert environments using
@code{LaTeX-declare-expert-environments}.

@defun LaTeX-declare-expert-environments @var{style} @var{environments}...
Declare @var{environments} as expert environments of @var{style}.

Expert environments are completed depending on @code{TeX-complete-expert-commands}.
@end defun


@node Adding Other
@subsection Adding or Examining Other Information
@cindex Adding bibliographies
@cindex Bibliographies, adding
@cindex Examining package/class options
@cindex package/class options, Examining
@cindex Viewer predicates
@cindex Defining bibliographies in style hooks
@cindex Adding labels
@cindex Labels, adding
@cindex Defining labels in style hooks
@cindex Adding other information
@cindex Other information, adding
@cindex Defining other information in style hooks

@subsubsection Adding bibliographies in style hooks

You can also specify bibliographical databases and labels in the style
file.  This is probably of little use, since this information will
usually be automatically generated from the @TeX{} file anyway.

@defun LaTeX-add-bibliographies @var{bibliography} @dots{}
Add each @var{bibliography} to list of loaded bibliographies.
@end defun

@defun LaTeX-add-labels @var{label} @dots{}
Add each @var{label} to the list of known labels.
@end defun

@subsubsection Examining package/class options

In @LaTeX{} documents, style hooks can find the package names and those
options given as optional argument(s) of @code{\usepackage} in
@code{LaTeX-provided-package-options}.

@defvar LaTeX-provided-package-options
Buffer local variable holding alist of options provided to @LaTeX{}
packages.  Each element is a cons cell @code{(@var{package}
. @var{option-list})}.  For example, its value will be
@lisp
  (("babel" . ("german"))
   ("geometry" . ("a4paper" "top=2cm" "bottom=2cm" "left=2.5cm" "right=2.5cm"))
   ...)
@end lisp
@end defvar

You can examine whether there is a specific package-option pair by
@code{LaTeX-provided-package-options-member}.

@defun LaTeX-provided-package-options-member @var{package} @var{option}
Return non-@code{nil} if @var{option} has been given to @var{package}.
The value is actually the tail of the list of options given to
@var{package}.
@end defun

There are similar facilities for class names and those options given in
@code{\documentclass} declaration.

@defvar LaTeX-provided-class-options
Buffer local variable holding alist of options provided to @LaTeX{}
classes.  Each element is a cons cell @code{(@var{class}
. @var{option-list})}.  For example, its value will be
@lisp
  (("book" . ("a4paper" "11pt" "openany" "fleqn"))
   ...)
@end lisp
@end defvar

@defun LaTeX-provided-class-options-member @var{class} @var{option}
Return non-@code{nil} if @var{option} has been given to @var{class}.  The
value is actually the tail of the list of options given to @var{class}.
@end defun

@defun LaTeX-match-class-option @var{regexp}
Check if a documentclass option matching @var{regexp} is active.  Return
first found class option matching @var{regexp}, or nil if not found.
@end defun

These functions are also useful to implement customized predicate(s) in
@code{TeX-view-predicate-list}.  @xref{Starting Viewers}.

@node Hacking the Parser
@subsection Automatic Extraction of New Things
@cindex Parsing new macros
@cindex @file{macro.tex}
@cindex @file{macro.el}
@cindex Changing the parser

The automatic @TeX{} information extractor works by searching for
regular expressions in the @TeX{} files, and storing the matched
information.  You can add support for new constructs to the parser,
something that is needed when you add new commands to define symbols.

For example, in the file @file{macro.tex} I define the following macro.

@example
\newcommand@{\newmacro@}[5]@{%
\def#1@{#3\index@{#4@@#5~cite@{#4@}@}\nocite@{#4@}@}%
\def#2@{#5\index@{#4@@#5~cite@{#4@}@}\nocite@{#4@}@}%
@}
@end example

@AUCTeX{} will automatically figure out that @samp{newmacro} is a macro
that takes five arguments.  However, it is not smart enough to
automatically see that each time we use the macro, two new macros are
defined.  We can specify this information in a style hook file.

@lisp
;;; macro.el --- Special code for my own macro file.

;;; Code:

(defvar TeX-newmacro-regexp
  '("\\\\newmacro@{\\\\\\([a-zA-Z]+\\)@}@{\\\\\\([a-zA-Z]+\\)@}"
    (1 2) TeX-auto-multi)
  "Matches \\newmacro definitions.")

(defvar TeX-auto-multi nil
  "Temporary for parsing \\newmacro definitions.")

(defun TeX-macro-cleanup ()
  "Move symbols from `TeX-auto-multi' to `TeX-auto-symbol'."
  (mapc (lambda (list)
          (mapc (lambda (symbol)
                  (setq TeX-auto-symbol
                        (cons symbol TeX-auto-symbol)))
                list))
        TeX-auto-multi))

(defun TeX-macro-prepare ()
  "Clear `Tex-auto-multi' before use."
  (setq TeX-auto-multi nil))

(add-hook 'TeX-auto-prepare-hook #'TeX-macro-prepare)
(add-hook 'TeX-auto-cleanup-hook #'TeX-macro-cleanup)

(TeX-add-style-hook
 "macro"
 (lambda ()
   (TeX-auto-add-regexp TeX-newmacro-regexp)
   (TeX-add-symbols '("newmacro"
                      TeX-arg-macro
                      (TeX-arg-macro "Capitalized macro: \\")
                      t
                      "BibTeX entry: "
                      nil))))

;;; macro.el ends here
@end lisp

When this file is first loaded, it adds a new entry to
@code{TeX-newmacro-regexp}, and defines a function to be called before
the parsing starts, and one to be called after the parsing is done.  It
also declares a variable to contain the data collected during parsing.
Finally, it adds a style hook which describes the @samp{newmacro} macro,
as we have seen it before.

So the general strategy is: Add a new entry to @code{TeX-newmacro-regexp}.
Declare a variable to contain intermediate data during parsing.  Add hook
to be called before and after parsing.  In this case, the hook before
parsing just initializes the variable, and the hook after parsing
collects the data from the variable, and adds them to the list of symbols
found.

@defvar TeX-auto-regexp-list
List of regular expressions matching @TeX{} macro definitions.

The list has the following format ((@var{regexp} @var{match} @var{table}) @dots{}), that
is, each entry is a list with three elements.

@var{regexp}.  Regular expression matching the macro we want to parse.

@var{match}.  A number or list of numbers, each representing one
parenthesized subexpression matched by @var{regexp}.

@var{table}.  The symbol table to store the data.  This can be a function, in
which case the function is called with the argument @var{match}.  Use
@code{TeX-match-buffer} to get match data.  If it is not a function, it
is presumed to be the name of a variable containing a list of match
data.  The matched data (a string if @var{match} is a number, a list of
strings if @var{match} is a list of numbers) is put in front of the table.
@end defvar

@defvar TeX-auto-prepare-hook nil
List of functions to be called before parsing a @TeX{} file.
@end defvar

@defvar TeX-auto-cleanup-hook nil
List of functions to be called after parsing a @TeX{} file.
@end defvar

@node Appendices
@appendix Copying, Changes, Development, FAQ, Texinfo Mode

@menu
* Copying this Manual::         
* Changes::                     
* Development::                 
* FAQ::                         
* Texinfo mode::                
@end menu

@node Copying this Manual
@appendixsec Copying this Manual

@ifinfo
The copyright notice for this manual is:

@insertcopying
@end ifinfo

The full license text can be read here:

@menu
* GNU Free Documentation License:: License for copying this manual.
@end menu

@lowersections
@include fdl.texi
@raisesections

@node Changes
@appendixsec Changes and New Features

@lowersections
@include changes.texi
@raisesections

@subheading Older versions
See the file @file{history.texi} for older changes.

@node Development
@appendixsec Future Development

@lowersections
@include todo.texi
@raisesections

@node FAQ
@appendixsec Frequently Asked Questions

@lowersections
@include faq.texi
@raisesections

@node Texinfo mode
@appendixsec Features specific to @AUCTeX{}'s Texinfo major mode

@AUCTeX{} includes a major mode for editting Texinfo files.  This major
mode is not the same mode as the native Texinfo mode (@pxref{Texinfo Mode,,,
texinfo,Texinfo}) of Emacs, although they have the same name.  However,
@AUCTeX{} still relies on a number of functions from the native Texinfo
mode.

The following text describes which functionality is offered by @AUCTeX{}
and which by the native Texinfo mode.  This should enable you to decide
when to consult the @AUCTeX{} manual and when the manual of the native
mode.  And in case you are a seasoned user of the native mode, the
information should help you to swiftly get to know the
@AUCTeX{}-specific commands.

@menu
* Exploiting::                  How @AUCTeX{} and the native mode work together
* Superseding::                 Where the native mode is superseded
* Mapping::                     Where key bindings are mapped to the native mode
* Unbinding::                   Which native mode key bindings are missing
@end menu

@node Exploiting
@appendixsubsec How @AUCTeX{} and the native mode work together

In a nutshell the split between @AUCTeX{} Texinfo mode, and native
Texinfo mode is as follows:

@itemize
@item
Most of the editing (environment creation, commenting, font command
insertions) and/or processing commands (e.g.@: compiling or printing)
which are available in other @AUCTeX{} modes are also handled by
@AUCTeX{} in Texinfo mode.

@item
Texinfo-related features (e.g.@: info node linkage or menu creation) rely
on the commands provided by the native Texinfo mode.  @AUCTeX{} provides
the key bindings to reach these functions, keeping the same keys as in
native Texinfo whenever possible, or similar ones otherwise.
@end itemize

@node Superseding
@appendixsubsec Where the native mode is superseded

This section is directed to users of the native Texinfo mode switching
to @AUCTeX{}.  It follows the summary of the native mode
(@pxref{Texinfo Mode Summary,,,texinfo,Texinfo}) and lists which of its commands
are no longer of use.

@table @asis
@item Insert commands
In the native Texinfo mode, frequently used Texinfo commands can be
inserted with key bindings of the form @kbd{C-c C-c @var{k}} where
@var{k} differs for each Texinfo command; @kbd{c} inserts @code{@@code},
@kbd{d} inserts @code{@@dfn}, @kbd{k} @code{@@kbd}, etc.

In @AUCTeX{} commands are inserted with the key binding @kbd{C-c C-m}
instead which prompts for the macro to be inserted.  For font selection
commands (like @code{@@b}, @code{@@i}, or @code{@@emph}) and a few related ones (like @code{@@var},
@code{@@key} or @code{@@code}) there are bindings which insert the respective macros
directly.  They have the form @kbd{C-c C-f @var{k}} or @kbd{C-c C-f
C-@var{k}} and call the function @code{TeX-font}.  Type @kbd{C-c C-f
@key{RET}} to get a list of supported commands.

Note that the prefix argument is not handled the same way by @AUCTeX{}.
Note also that the node insertion command from the native mode
(@code{texinfo-insert-@@node}) can still accessed from the Texinfo menu
in @AUCTeX{}.

@item Insert braces
In @AUCTeX{} braces can be inserted with the same key binding as in the
native Texinfo mode: @kbd{C-c @{}.  But @AUCTeX{} uses its own function
for the feature: @code{TeX-insert-braces}.

@item Insert environments
The native Texinfo mode does not insert full environments.  Instead, it
provides the function @code{texinfo-insert-@@end} (mapped to @kbd{C-c
C-c e}) for closing an open environment with a matching @code{@@end} statement.

In @AUCTeX{} you can insert full environments, i.e.@: both the opening and
closing statements, with the function @code{Texinfo-environment} (mapped
to @kbd{C-c C-e}).

@item Format info files with makeinfo and @TeX{}
In the native Texinfo mode there are various functions and bindings to
format a region or the whole buffer for info or to typeset the
respective text.  For example, there is @code{makeinfo-buffer} (mapped
to @kbd{C-c C-m C-b}) which runs @samp{makeinfo} on the buffer or there
is @code{texinfo-tex-buffer} (mapped to @kbd{C-c C-t C-b}) which runs
@TeX{} on the buffer in order to produce a @acronym{DVI} file.

In @AUCTeX{} different commands for formatting or typesetting can be
invoked through the function @code{TeX-command-master} (mapped to
@kbd{C-c C-c}).  After typing @kbd{C-c C-c}, you can select the desired
command, e.g @samp{Makeinfo} or @samp{TeX}, through a prompt in the mini
buffer.  Note that you can make, say @samp{Makeinfo}, the default by
adding this statement in your init file:

@lisp
(add-hook 'Texinfo-mode-hook 
          (lambda () (setq TeX-command-default "Makeinfo")))
@end lisp

Note also that @kbd{C-c C-c Makeinfo @key{RET}} is not completely
functionally equivalent to @code{makeinfo-buffer} as the latter will
display the resulting info file in Emacs, showing the node corresponding
to the position in the source file, just after a successful compilation.
This is why, while using @AUCTeX{}, invoking @code{makeinfo-buffer}
might still be more convenient.

Note also that in the case of a multifile document, @kbd{C-c C-c} in
@AUCTeX{} will work on the whole document (provided that the file
variable @code{TeX-master} is set correctly), while
@code{makeinfo-buffer} in the native mode will process only the current
buffer, provided at the @code{@@setfilename} statement is provided.

@item Produce indexes and print
The native Texinfo mode provides the binding @kbd{C-c C-t C-i}
(@code{texinfo-texindex}) for producing an index and the bindings
@kbd{C-c C-t C-p} (@code{texinfo-tex-print}) and @kbd{C-c C-t C-q}
(@code{tex-show-print-queue}) for printing and showing the printer
queue.  These are superseded by the respective commands available
through @kbd{C-c C-c} (@code{TeX-command-master}) in @AUCTeX{}: @samp{Index},
@samp{Print}, and @samp{Queue}.
@c FIXME: "Index" runs makeindex, not texindex.  No entry in
@c TeX-command-list runs texindex.

@item Kill jobs
The command @kbd{C-c C-t C-k} (@code{tex-kill-job}) in the native mode
is superseded by @kbd{C-c C-k} (@code{TeX-kill-job}) in @AUCTeX{}.
@end table

@node Mapping
@appendixsubsec Where key bindings are mapped to the native mode

This node follows the native Texinfo mode summary (@pxref{Texinfo Mode
Summary,,,texinfo,Texinfo}) and lists only those commands to which @AUCTeX{}
provides a keybinding.

Basically all commands of the native mode related to producing menus and
interlinking nodes are mapped to same or similar keys in @AUCTeX{},
while a few insertion commands are mapped to @AUCTeX{}-like keys.

@table @asis

@item @code{@@item} insertion
The binding @kbd{C-c C-c i} for the insertion of @code{@@item} in the
native mode is mapped to @kbd{M-@key{RET}} or @kbd{C-c C-j} in
@AUCTeX{}, similar to other @AUCTeX{} modes.

@item @code{@@end} insertion
The binding @kbd{C-c C-c e} for closing a @code{@@@var{foo}} command by
a corresponding @code{@@end @var{foo}} statement in the native mode is
mapped to @kbd{C-c ]} in @AUCTeX{}, similar to other @AUCTeX{} modes.

@item Move out of balanced braces
The binding @kbd{C-c @}} (@code{up-list}) is available both in the native
mode and in @AUCTeX{}.  (This is because the command is not implemented
in either mode but a native Emacs command.)  However, in @AUCTeX{}, you
cannot use @kbd{C-c ]} for this, as it is used for @code{@@end} insertion.

@item Update pointers
The bindings @kbd{C-c C-u C-n} (@code{texinfo-update-node}) and @kbd{C-c
C-u C-e} (@code{texinfo-every-node-update}) from the native mode are
available in @AUCTeX{} as well.

@item Update menus
The bindings @kbd{C-c C-u m} (@code{texinfo-master-menu}), @kbd{C-c C-u
C-m} (@code{texinfo-make-menu}), and @kbd{C-c C-u C-a}
(@code{texinfo-all-menus-update}) from the native mode are available in
@AUCTeX{} as well.  The command @code{texinfo-start-menu-description},
bound to @kbd{C-c C-c C-d} in the native mode, is bound to @kbd{C-c C-u
C-d} in @AUCTeX{} instead.
@end table

@node Unbinding
@appendixsubsec Which native mode key bindings are missing

The following commands from the native commands might still be useful
when working with @AUCTeX{}, however, they are not accessible with a
key binding any longer.

@table @asis
@item @code{@@node} insertion
The node insertion command, mapped to @kbd{C-c C-c n} in the native
mode, is not mapped to any key in @AUCTeX{}.  You can still access it
through the Texinfo menu, though.  Another alternative is to use the
@kbd{C-c C-m} binding for macro insertion in @AUCTeX{}.

@item Show the section structure
The command @code{texinfo-show-structure} (@kbd{C-c C-s}) from the
native mode does not have a key binding in @AUCTeX{}.  The binding is
used by @AUCTeX{} for sectioning.
@end table

@node Indices
@unnumbered Indices

@menu
* Key Index::                   
* Function Index::              
* Variable Index::              
* Concept Index::               
@end menu

@node Key Index
@unnumberedsec Key Index

@printindex ky

@node Function Index
@unnumberedsec Function Index

@printindex fn

@node Variable Index
@unnumberedsec Variable Index

@printindex vr

@node Concept Index
@unnumberedsec Concept Index

@printindex cp

@bye

@c Local Variables:
@c mode: texinfo
@c coding: utf-8
@c TeX-master: t
@c End:
