Structure your text into divisions: parts, chapters, sections, etc. All sectioning commands have the same form, one of:
sectioning-command{title} sectioning-command*{title} sectioning-command[toc-title]{title}
For instance, declare the start of a subsection as with
\subsection{Motivation}
.
The table has each sectioning-command in LaTeX. All are
available in all of LaTeX’s standard document classes book
,
report
, and article
, except that \chapter
is
not available in article
.
Sectioning unit | Command | Level |
---|---|---|
Part | \part | -1 (book , report ), 0 (article ) |
Chapter | \chapter | 0 |
Section | \section | 1 |
Subsection | \subsection | 2 |
Subsubsection | \subsubsection | 3 |
Paragraph | \paragraph | 4 |
Subparagraph | \subparagraph | 5 |
All these commands have a *
-form that prints title as usual
but is not numbered and does not make an entry in the table of contents.
An example of using this is for an appendix in an article
. The
input \appendix\section{Appendix}
gives the output ‘A
Appendix’ (see \appendix). You can lose the numbering ‘A’
by instead entering \section*{Appendix}
(articles often omit a
table of contents and have simple page headers so the other differences
from the \section
command may not matter).
The section title title provides the heading in the main text, but it may also appear in the table of contents and in the running head or foot (see Page styles). You may not want the same text in these places as in the main text. All of these commands have an optional argument toc-title for these other places.
The level number in the table above determines which sectional units are
numbered, and which appear in the table of contents. If the sectioning
command’s level is less than or equal to the value of the counter
secnumdepth
then the titles for this sectioning command will be
numbered (see Sectioning/secnumdepth). And, if level is less
than or equal to the value of the counter tocdepth
then the table
of contents will have an entry for this sectioning unit
(see Sectioning/tocdepth).
LaTeX expects that before you have a \subsection
you will have
a \section
and, in a book, that before a \section
you will
have a \chapter
. Otherwise you can get a something like a
subsection numbered ‘3.0.1’.
Two counters relate to the appearance of sectioning commands.
secnumdepth
Controls which sectioning commands are
numbered. Suppress numbering of sectioning at any depth greater than
level \setcounter{secnumdepth}{level}
(see \setcounter). See the above table for the level numbers. For
instance, if the secnumdepth
is 1 in an article
then a
\section{Introduction}
command will produce output like ‘1
Introduction’ while \subsection{Discussion}
will produce output
like ‘Discussion’, without the number. LaTeX’s default
secnumdepth
is 3 in article class and 2 in the
book and report classes.
tocdepth
Controls which sectioning units are listed in the table of contents.
The setting \setcounter{tocdepth}{level}
makes the
sectioning units at level be the smallest ones listed
(see \setcounter). See the above table for the level numbers. For
instance, if tocdepth
is 1 then the table of contents will
list sections but not subsections. LaTeX’s default
secnumdepth
is 3 in article class and 2 in the
book and report classes.
\part
Synopsis, one of:
\part{title} \part*{title} \part[toc-title]{title}
Start a document part. The standard LaTeX classes book
,
report
, and article
, all have this command.
This produces a document part, in a book.
\part{VOLUME I \\ PERSONAL MEMOIRS OF U.\ S.\ GRANT} \chapter{ANCESTRY--BIRTH--BOYHOOD.} My family is American, and has been for generations, in all its branches, direct and collateral.
In each standard class the \part
command outputs a part number
such as ‘Part I’, alone on its line, in boldface, and in large
type. Then LaTeX outputs title, also alone on its line, in
bold and in even larger type. In class book
, the LaTeX
default puts each part alone on its own page. If the book is two-sided
then LaTeX will skip a page if needed to have the new part on an
odd-numbered page. In report
it is again alone on a page, but
LaTeX won’t force it onto an odd-numbered page. In an article
LaTeX does not put it on a fresh page, but instead outputs the part
number and part title onto the main document page.
The *
form shows title
but it does not show the part number, does not increment the
part
counter, and produces no table of contents entry.
The optional argument toc-title will appear as the part title in the table of contents (see Table of contents etc.) and in running headers (see Page styles). If it is not present then title will be there. This example puts a line break in title but leaves out the break in the table of contents.
\part[Up from the bottom; my life]{Up from the bottom\\ my life}
For determining which sectional units are numbered and which appear in the table of contents, the level number of a part is -1 (see Sectioning/secnumdepth and see Sectioning/tocdepth).
In the class article
, if a paragraph immediately follows the part
title then it is not indented. To get an indent you can use the package
indentfirst.
One package to change the behavior of \part
is titlesec.
See its documentation on CTAN.
\chapter
Synopsis, one of:
\chapter{title} \chapter*{title} \chapter[toc-title]{title}
Start a chapter. The standard LaTeX classes book
and
report
have this command but article
does not.
This produces a chapter.
\chapter{Loomings} Call me Ishmael. Some years ago---never mind how long precisely---having little or no money in my purse, and nothing particular to interest me on shore, I thought I would sail about a little and see the watery part of the world.
The LaTeX default starts each chapter on a fresh page, an
odd-numbered page if the document is two-sided. It produces a chapter
number such as ‘Chapter 1’ in large boldface type (the size is
\huge
). It then puts title on a fresh line, in boldface
type that is still larger (size \Huge
). It also increments the
chapter
counter, adds an entry to the table of contents
(see Table of contents etc.), and sets the running header
information (see Page styles).
The *
form shows title on a fresh line, in boldface.
But it does not show the chapter number, does not increment the
chapter
counter, produces no table of contents entry, and does
not affect the running header. (If you use the page style
headings
in a two-sided document then the header will be from the
prior chapter.) This example illustrates.
\chapter*{Preamble}
The optional argument toc-title will appear as the chapter title in the table of contents (see Table of contents etc.) and in running headers (see Page styles). If it is not present then title will be there. This shows the full name in the chapter title,
\chapter[Weyl]{Hermann Klaus Hugo (Peter) Weyl (1885--1955)}
but only ‘Weyl’ on the contents page. This puts a line break in the title but that doesn’t work well with running headers so it omits the break in the contents
\chapter[Given it all\\ my story]{Given it all\\ my story}
For determining which sectional units are numbered and which appear in the table of contents, the level number of a chapter is 0 (see Sectioning/secnumdepth and see Sectioning/tocdepth).
The paragraph that follows the chapter title is not indented, as is a standard typographical practice. To get an indent use the package indentfirst.
You can change what is shown for the chapter number. To change it to
something like ‘Lecture 1’, put in the preamble either
\renewcommand{\chaptername}{Lecture}
or this
(see \makeatletter & \makeatother).
\makeatletter \renewcommand{\@chapapp}{Lecture} \makeatother
To make this change because of the primary language for the document, see the package babel.
In a two-sided document LaTeX puts a chapter on odd-numbered page, if necessary leaving an even-numbered page that is blank except for any running headers. To make that page completely blank, see \clearpage & \cleardoublepage.
To change the behavior of the \chapter
command, you can copy its
definition from the LaTeX format file and make adjustments. But
there are also many packages on CTAN that address this. One is
titlesec. See its documentation, but the example below gives a
sense of what it can do.
\usepackage{titlesec} % in preamble \titleformat{\chapter} {\Huge\bfseries} % format of title {} % label, such as 1.2 for a subsection {0pt} % length of separation between label and title {} % before-code hook
This omits the chapter number ‘Chapter 1’ from the page but unlike
\chapter*
it keeps the chapter in the table of contents and the
running headers.
\section
Synopsis, one of:
\section{title} \section*{title} \section[toc-title]{title}
Start a section. The standard LaTeX classes article
,
book
, and report
all have this command.
This produces a section.
In this Part we tend to be more interested in the function, in the input-output behavior, than in the details of implementing that behavior. \section{Turing machines} Despite this desire to downplay implementation, we follow the approach of A~Turing that the first step toward defining the set of computable functions is to reflect on the details of what mechanisms can do.
For the standard LaTeX classes book
and report
the
default output is like ‘1.2 title’ (for chapter 1,
section 2), alone on its line and flush left, in boldface and a
larger type (the type size is \Large
). The same holds in
article
except that there are no chapters in that class so it
looks like ‘2 title’.
The *
form shows title.
But it does not show the section number, does not increment the
section
counter, produces no table of contents entry, and does
not affect the running header. (If you use the page style
headings
in a two-sided document then the header will be from the
prior section.)
The optional argument toc-title will appear as the section title in the table of contents (see Table of contents etc.) and in running headers (see Page styles). If it is not present then title will be there. This shows the full name in the title of the section,
\section[Elizabeth~II]{Elizabeth the Second, by the Grace of God of the United Kingdom, Canada and Her other Realms and Territories Queen, Head of the Commonwealth, Defender of the Faith.}
but only ‘Elizabeth II’ on the contents page and in the headers. This has a line break in title but that does not work with headers so it is omitted from the contents and headers.
\section[Truth is, I cheated; my life story]{Truth is, I cheated\\my life story}
For determining which sectional units are numbered and which appear in the table of contents, the level number of a section is 1 (see Sectioning/secnumdepth and see Sectioning/tocdepth).
The paragraph that follows the section title is not indented, as is a standard typographical practice. One way to get an indent is to use the package indentfirst.
In general, to change the behavior of the \section
command, there
are a number of options. One is the \@startsection
command
(see \@startsection). There are also many packages on CTAN that
address this, including titlesec. See the documentation but the
example below gives a sense of what they can do.
\usepackage{titlesec} % in preamble \titleformat{\section} {\normalfont\Large\bfseries} % format of title {\makebox[1pc][r]{\thesection\hspace{1pc}}} % label {0pt} % length of separation between label and title {} % before-code hook \titlespacing*{\section} {-1pc}{18pt}{10pt}[10pc]
That puts the section number in the margin.
\subsection
Synopsis, one of:
\subsection{title} \subsection*{title} \subsection[toc-title]{title}
Start a subsection. The standard LaTeX classes article
,
book
, and report
all have this command.
This produces a subsection.
We will show that there are more functions than Turing machines and that therefore some functions have no associated machine. \subsection{Cardinality} We will begin with two paradoxes that dramatize the challenge to our intuition posed by comparing the sizes of infinite sets.
For the standard LaTeX classes book
and report
the
default output is like ‘1.2.3 title’ (for chapter 1,
section 2, subsection 3), alone on its line and flush left, in
boldface and a larger type (the type size is \large
). The same
holds in article
except that there are no chapters in that class
so it looks like ‘2.3 title’.
The *
form shows title.
But it does not show the section number, does not increment the
section
counter, and produces no table of contents entry.
The optional argument toc-title will appear as the section title in the table of contents (see Table of contents etc.). If it is not present then title will be there. This shows the full name in the title of the section,
\subsection[$\alpha,\beta,\gamma$ paper]{\textit{The Origin of Chemical Elements} by R.A.~Alpher, H.~Bethe, and G.~Gamow}
but only ‘α,β,γ paper’ on the contents page.
For determining which sectional units are numbered and which appear in the table of contents, the level number of a subsection is 2 (see Sectioning/secnumdepth and see Sectioning/tocdepth).
The paragraph that follows the subsection title is not indented, as is a standard typographical practice. One way to get an indent is to use the package indentfirst.
There are a number of ways to change the behavior of the
\subsection
command. One is the \@startsection
command
(see \@startsection). There are also many packages on CTAN that
address this, including titlesec. See the documentation but the
example below gives a sense of what they can do.
\usepackage{titlesec} % in preamble \titleformat{\subsection}[runin] {\normalfont\normalsize\bfseries} % format of the title {\thesubsection} % label {0.6em} % space between label and title {} % before-code hook
That puts the subsection number and title in the first line of text.
\subsubsection
, \paragraph
, \subparagraph
Synopsis, one of:
\subsubsection{title} \subsubsection*{title} \subsubsection[toc-title]{title}
or one of:
\paragraph{title} \paragraph*{title} \paragraph[toc-title]{title}
or one of:
\subparagraph{title} \subparagraph*{title} \subparagraph[toc-title]{title}
Start a subsubsection, paragraph, or subparagraph. The standard
LaTeX classes article
, book
, and report
all have
these commands, although they are not commonly used.
This produces a subsubsection.
\subsubsection{Piston ring compressors: structural performance} Provide exterior/interior wall cladding assemblies capable of withstanding the effects of load and stresses from consumer-grade gasoline engine piston rings.
The default output of each of the three does not change over the
standard LaTeX classes article
, book
, and
report
. For \subsubsection
the title is alone on
its line, in boldface and normal size type. For \paragraph
the
title is inline with the text, not indented, in boldface and
normal size type. For \subparagraph
the title is inline
with the text, with a paragraph indent, in boldface and normal size type
(Because an article
has no chapters its subsubsections are
numbered and so it looks like ‘1.2.3 title’, for
section 1, subsection 2, and subsubsection 3. The other
two divisions are not numbered.)
The *
form shows title. But it does not increment the
associated counter and produces no table of contents entry (and does not
show the number for \subsubsection
).
The optional argument toc-title will appear as the division title in the table of contents (see Table of contents etc.). If it is not present then title will be there.
For determining which sectional units are numbered and which appear in the table of contents, the level number of a subsubsection is 3, of a paragraph is 4, and of a subparagraph is 5 (see Sectioning/secnumdepth and see Sectioning/tocdepth).
The paragraph that follows the subsubsection title is not indented, as is a standard typographical practice. One way to get an indent is to use the package indentfirst.
There are a number of ways to change the behavior of the these commands.
One is the \@startsection
command (see \@startsection).
There are also many packages on CTAN that address this, including
titlesec. See the documentation on CTAN.
\appendix
Synopsis:
\appendix
This does not directly produce any output. But in a book or report it
declares that subsequent \chapter
commands start an appendix. In
an article it does the same, for \section
commands. It also
resets the chapter
and section
counters to 0 in a
book or report, and in an article resets the section
and
subsection
counters.
In this book
\chapter{One} ... \chapter{Two} ... ... \appendix \chapter{Three} ... \chapter{Four} ...
the first two will generate output numbered ‘Chapter 1’ and
‘Chapter 2’. After the \appendix
the numbering will be
‘Appendix A’ and ‘Appendix B’. See Larger book template
for another example.
The appendix package adds the command
\appendixpage
to put a separate ‘Appendices’ in the document
body before the first appendix, and the command \addappheadtotoc
to do the same in the table of contents. You can reset the name
‘Appendix’ with a command like
\renewcommand{\appendixname}{Specification}
, as well as a
number of other features. See the documentation on CTAN.
\frontmatter
, \mainmatter
, \backmatter
Synopsis, one of:
\frontmatter \mainmatter \backmatter
Format a book
class document differently according to which part
of the document is being produced. All three commands are optional.
Traditionally, a book’s front matter contains such things as the title page, an abstract, a table of contents, a preface, a list of notations, a list of figures, and a list of tables. (Some of these front matter pages, such as the title page, are traditionally not numbered.) The back matter may contain such things as a glossary, notes, a bibliography, and an index.
The \frontmatter
declaration makes the pages numbered in
lowercase roman, and makes chapters not numbered, although each
chapter’s title appears in the table of contents; if you use other
sectioning commands here, use the *
-version (see Sectioning).
The \mainmatter
changes the behavior back to the expected
version, and resets the page number. The \backmatter
leaves the
page numbering alone but switches the chapters back to being not
numbered. See Larger book template for an example using the three.
\@startsection
Synopsis:
\@startsection{name}{level}{indent}{beforeskip}{afterskip}{style}
Used to help redefine the behavior of commands that start sectioning
divisions such as \section
or \subsection
.
Note that the titlesec package makes manipulation of sectioning
easier. Further, while most requirements for sectioning commands can be
satisfied with \@startsection
, some cannot. For instance, in
the standard LaTeX book
and report
classes the commands
\chapter
and \report
are not constructed in this way. To
make such a command you may want to use the \secdef
command.
Technically, \@startsection
has the form
\@startsection{name} {level} {indent} {beforeskip} {afterskip} {style}*[toctitle]{title}
so that issuing
\renewcommand{\section}{\@startsection{name} {level} {indent} {beforeskip} {afterskip} {style}}
redefines \section
to have the form
\section*[toctitle]{title}
(here too, the
star *
is optional). See Sectioning. This implies that
when you write a command like \renewcommand{section}{...}
,
the \@startsection{...}
must come last in the definition. See
the examples below.
Name of the counter used to number the sectioning header. This counter
must be defined separately. Most commonly this is either
section
, subsection
, or paragraph
. Although in
those cases the counter name is the same as the sectioning command
itself, you don’t have to use the same name.
Then \the
name displays the title number and
\
namemark
is for the page headers. See the third
example below.
An integer giving the depth of the sectioning command. See Sectioning for the list of standard level numbers.
If level is less than or equal to the value of the counter
secnumdepth
then titles for this sectioning command will be
numbered (see Sectioning/secnumdepth). For instance, if
secnumdepth
is 1 in an article
then the command
\section{Introduction}
will produce output like “1
Introduction” while \subsection{Discussion}
will produce
output like “Discussion”, without the number prefix.
If level is less than or equal to the value of the counter
tocdepth then the table of contents will have an entry for this
sectioning unit (see Sectioning/tocdepth). For instance, in an
article
, if tocdepth is 1 then the table of contents will
list sections but not subsections.
A length giving the indentation of all of the title lines with respect
to the left margin. To have the title flush with the margin use
0pt
. A negative indentation such as -\parindent
will move
the title into the left margin.
The absolute value of this length is the amount of vertical space that
is inserted before this sectioning unit’s title. This space will be
discarded if the sectioning unit happens to start at the top of a fresh
page. If this number is negative then the first paragraph following the
header is not indented, if it is non-negative then the first paragraph
is indented. (Note that the negative of 1pt plus 2pt minus 3pt
is -1pt plus -2pt minus -3pt
.)
For example, if beforeskip is -3.5ex plus -1ex minus -0.2ex
then to start the new sectioning unit, LaTeX will add about 3.5 times
the height of a letter x in vertical space, and the first paragraph in
the section will not be indented. Using a rubber length, with
plus
and minus
, is good practice here since it gives
LaTeX more flexibility in making up the page (see Lengths).
The full accounting of the vertical space between the baseline of the
line prior to this sectioning unit’s header and the baseline of the
header is that it is the sum of the \parskip
of the text font,
the \baselineskip
of the title font, and the absolute value of
the beforeskip. This space is typically rubber so it may stretch
or shrink. (If the sectioning unit starts on a fresh page so that the
vertical space is discarded then the baseline of the header text will be
where LaTeX would put the baseline of the first text line on that
page.)
This is a length. If afterskip is non-negative then this is the
vertical space inserted after the sectioning unit’s title header. If it
is negative then the title header becomes a run-in header, so that it
becomes part of the next paragraph. In this case the absolute value of
the length gives the horizontal space between the end of the title and
the beginning of the following paragraph. (Note that the negative of
1pt plus 2pt minus 3pt
is -1pt plus -2pt minus -3pt
.)
As with beforeskip, using a rubber length, with plus
and
minus
components, is good practice here since it gives LaTeX
more flexibility in putting together the page.
If afterskip
is non-negative then the full accounting of the
vertical space between the baseline of the sectioning unit’s header and
the baseline of the first line of the following paragraph is that it is
the sum of the \parskip
of the title font, the
\baselineskip
of the text font, and the value of after.
That space is typically rubber so it may stretch or shrink. (Note that
because the sign of afterskip
changes the sectioning unit
header’s from standalone to run-in, you cannot use a negative
afterskip
to cancel part of the \parskip
.)
Controls the styling of the title. See the examples below. Typical
commands to use here are \centering
, \raggedright
,
\normalfont
, \hrule
, or \newpage
. The last command
in style may be one that takes one argument, such as
\MakeUppercase
or \fbox
that takes one argument. The
section title will be supplied as the argument to this command. For
instance, setting style to \bfseries\MakeUppercase
would
produce titles that are bold and uppercase.
These are LaTeX’s defaults for the first three sectioning units that
are defined with \@startsection
, for the article,
book, and report classes. For section, the level is
1, the indent is 0pt, the beforeskip is -3.5ex
plus -1ex minus -0.2ex
, the afterskip is 2.3ex plus 0.2ex
,
and the style is \normalfont\Large\bfseries
. For
subsection, the level is 2, the indent is 0pt, the
beforeskip is -3.25ex plus -1ex minus -0.2ex
, the
afterskip is 1.5ex plus 0.2ex
, and the style is
\normalfont\large\bfseries
. For subsubsection, the level
is 3, the indent is 0pt, the beforeskip is
-3.25ex plus -1ex minus -0.2ex
, the afterskip is
1.5ex plus 0.2ex
, and the style is
\normalfont\normalsize\bfseries
.
Here are examples. They go either in a package or class file or in the
preamble of a LaTeX document. If you put them in the preamble they
must go between a \makeatletter
command and a
\makeatother
. (Probably the error message You can't use
`\spacefactor' in vertical mode.
means that you forgot this.)
See \makeatletter & \makeatother.
This will put section titles in large boldface type, centered. It says
\renewcommand
because LaTeX’s standard classes have already
defined a \section
. For the same reason it does not define a
section
counter, or the commands \thesection
and
\l@section
.
\renewcommand\section{% \@startsection{section}% name {1}% level {0pt}% indent {-3.5ex plus -1ex minus -.2ex}% beforeskip {2.3ex plus.2ex}% afterskip {\centering\normalfont\Large\bfseries}% style }
This will put subsection
titles in small caps type, inline with the paragraph.
\renewcommand\subsection{% \@startsection{subsection}% name {2}% level {0em}% indent {-1ex plus 0.1ex minus -0.05ex}% beforeskip {-1em plus 0.2em}% afterskip {\scshape}% style }
The prior examples redefined existing sectional unit title commands. This defines a new one, illustrating the needed counter and macros to display that counter.
\setcounter{secnumdepth}{6}% show counters this far down \newcounter{subsubparagraph}[subparagraph]% counter for numbering \renewcommand{\thesubsubparagraph}% how to display {\thesubparagraph.\@arabic\c@subsubparagraph}% numbering \newcommand{\subsubparagraph}{\@startsection {subsubparagraph}% {6}% {0em}% {\baselineskip}% {0.5\baselineskip}% {\normalfont\normalsize}} \newcommand*\l@subsubparagraph{\@dottedtocline{6}{10em}{5em}}% for toc \newcommand{\subsubparagraphmark}[1]{}% for page headers