LaTeX Typesetting Document Features︽

LaTeX Typeset Document︽

$\(\LaTeX\)$, created by Leslie Lamport, is a set of macros used to simplify $\(\TeX\)$ typesetting, whereas $\(\TeX\)$, created by Donald Knuth, is a low-level markup and programming language. $\(\LaTeX\)$ typeset document is a plain text file of rendered source text with $\(\LaTeX\)$ markup.

LaTeX Typeset Structure︽

$\(\LaTeX\)$ uses a tree like structure to model $\(\LaTeX\)$ typeset document. A $\(\LaTeX\)$ typeset document is mainly divided into two main divisions, the initial and preamble commands division and the document environment division. The document environment division begins with an opening command, "\begin{docunment}" and ends with and closing command, "\end{document}".

LaTeX Typeset Document Example︽

Code

\documentclass{standalone}
\begin{document} 
Hello world!
\end{document} 

Output

Spacing︽

In $\(\LaTeX\)$ typesetting document, space and line break are used as delimiter. Words are separated by spaces, while paragraphs are separated by blank lines, that is two or more consecutive line breaks. And a single line break alone is equivalent to a space. Although word space, line space, and paragraph space are automatically generated by $\(\LaTeX\)$ engine, these spacing can be specified through typesetting commands.

Space︽

Similar to other markup language, all whitespace characters are treated as a space. Several consecutive spaces are treated as one single space. Opening space of a line is always ignored. Word space, line space, and paragraph space

LaTeX Space Example︽

Code

\documentclass[variwidth]{standalone}
\begin{document} 
               Hello                         world!
\end{document} 

Output

Line Break︽

A single line break always yields a space. However, more then one consecutive line breaks, empty lines, may imply the end of a paragraph if applicable.

LaTeX Line Break Example 1︽

Code

\documentclass[varwidth]{standalone}
\begin{document} 
   Hello world! 
    Hello world!       Hello world! 
       
Hello world!
  
     
    Hello world!\par    Hello    world!



\end{document} 

Output

LaTeX Line Break Example 2︽

Code

\documentclass{standalone}
\begin{document} 
   Hello world! 
    Hello world!       Hello world! 
       
Hello world!
  
     
    Hello world!\par    Hello    world!



\end{document} 

Output

LaTeX Comment︽

$\(\LaTeX\)$ ignores the % character and the rest characters of the current line, including the line break. All whitespaces at the beginning of the next line will also be ignored because opening space of a line is always ignored.

LaTeX Comment Example︽

Code

%LaTeX Comment
\documentclass{standalone}
\begin{document} 
%LaTeX Comment
Hello world!
\end{document} 

Output

Special and Reserved Characters︽

Some symbols that are either having a special meaning in $\(\LaTeX\)$ or unavailable in all the fonts, are defined as reserved characters. These symbols are %, \, #, {, }, $, ^, _, ~, &, :, *, <, >, |, ', [, ], (, and ).

Reserved Characters︽

Some Characters are reserved for initializing a typesetting mechanism in $\(\LaTeX\)$.

LaTeX Reserved Character Example︽

Code

%Reserved Characters
\documentclass[varwidth]{standalone}
\usepackage{varwidth}
\newcommand\cmd[1]{#1}
\begin{document}
\begin{varwidth}{2.5cm}
$aaaa^2_i$ aaaa~hhhh hhh hh\\
$aaaa^2_i$ aaaa hhhh hhh hh
\end{varwidth}
\begin{tabular}{c c}
\#1 & \#2\\
\end{tabular}
\end{document} 

Output

Special Characters︽

The typesetting text for some characters are difference in text mode and math mode.

LaTeX Special Character Example︽

Code

\documentclass[varwidth]{standalone}
\begin{document}
\begin{tabular}{ccc}
Character & Text Mode & Math Mode\\
: & H:M & $H:M$\\
** & H*M & $H*M$\\
\textless & H<M & $H<M$\\
\textgreater & H>M & $H>M$\\
\textbar & H|M & $H|M$\\
\`{} & H`M & $H`M$\\
\end{tabular}
\end{document}

Output

Special Font Encoding︽

The two major font encodings, used for Latin languages are OT1 (Donald Knuth’s 7-bit encoding) and T1 (the new 8-bit ‘Cork’ encoding). LaTeX2e has support for both OT1 and T1 built-in. However, these two font encodings do not share the same set of characters.

LaTeX Font Encoding Example︽

Code

\documentclass[varwidth]{standalone}
\usepackage{multirow}
\begin{document}
\begin{tabular}{c|ccc}
Mode & Character & OT1  encoding & T1  encoding\\
\hline
\multirow{3}{*}{text mode}&\textless & H<M & {\fontencoding{T1}\selectfont H<M}\\
&\textgreater & H>M & {\fontencoding{T1}\selectfont H>M}\\
&\textbar & H|M & {\fontencoding{T1}\selectfont H|M}\\
\hline
\multirow{3}{*}{math mode}&\textless & $H<M$ & ${\fontencoding{T1}\selectfont H<M}$\\
&\textgreater & $H>M$ & ${\fontencoding{T1}\selectfont H>M}$\\
&\textbar & $H|M$ & ${\fontencoding {T1}\selectfont H|M}$\\
\end{tabular}
\end{document}

Output

Special Grouping Characters︽

LaTeX Grouping Characters Example︽

Code

\documentclass[varwidth]{standalone}
%  varwidth option
\begin{document}
aadkljfdsklfj \[x^2\] dfkdlfjslk \(x^2\) sd;fldskjfkds \[x^2\]
\end{document}

Output

Escape Characters︽

Escaped Characters can be used to represent reserved characters and to invoke an alternative interpretation on the following characters in a character sequence Escape CharacterCharacterRemarks \##"#" reserved to reference an arguments for a user defined command \$$"$" reserved to start and finish math mode \%%"%" reserved to specify a comment \&&"&" reserved as the alignment character \{{"{" reserved as an open delimiter to group and separate commands from its surroundings \}}"}" reserved as a close delimiter to group and separate commands from its surroundings \\a new paragraph"\" reserved to specify a command \textbackslash\ $\backslash$\ \_H_H"_"reserved to specify a subscript in math mode $H_{H}$HH \^HH"^" reserved to specify a superscript in math mode \^{}H^H \textasciicircum^ $\hat{}$^ $\^{H}$HH \~HH"~" reserved as an unbreakable space \~{}H~H \textasciitilde~ \texttildelow~ $\tilde{\ }$~ $\sim$~ $_\textrm{\symbol{126}}$~ $\|$‖ |an em dash (—). $|$| \textbar| $\vert$| $\mid$|

LaTeX Escape Characters Example︽

Code

\documentclass{standalone}
\usepackage{multirow}
\usepackage{makecell}
\def\arraystretch{1.3}
\begin{document}
\begin{tabular}{c|c|>{\centering\arraybackslash}p{12mm}|>{\centering\arraybackslash}p{12mm}|l}
Character&\thead{Escape\\Character}&\thead{text\\mode} &\thead{math\\ mode}&Remarks\\
\hline
\# & \textbackslash\# & \# & $\#$\\
\$ & \textbackslash\$ & \$ & $\$$\\
\% & \textbackslash\% & \% & $\%$\\
\& & \textbackslash\& & \& & $\&$\\
\{ & \textbackslash\{ & \{ & $\{$\\
\} & \textbackslash\} & \} & $\}$\\
\hline
\multirow{3}{*}{\textbackslash} & endline\textbackslash\textbackslash\ newline& \makecell{endline\\ newline} & $\makecell{endline\\ newline}$\\
& \textbackslash textbackslash & \textbackslash && text mode\\
& \$\textbackslash backslash\$ & & $\backslash$ & math mode\\
\hline
\multirow{2}{*}{\_} & H\textbackslash\_\{H\} & H\_{H} & $H\_{H}$ &\\
& \$H\_\{H\}\$ &  & $H_{H}$ & math mode\\
\hline
\multirow{4}{*}{\^} &\textbackslash\textasciicircum H & \^H & & text mode\\
&\textbackslash\^{}\{\}H & \^{}H &  & text mode\\
&\textbackslash textasciicircum & \textasciicircum & & text mode\\
&\$\textbackslash hat\{\}\$ & & $\hat{}$ & math mode\\
&\$H\textasciicircum\{H\}\$ & & $H^{H}$ & math mode\\
\hline
\multirow{9}{*}{\~} &\textbackslash\textasciitilde H & \~H & & text mode\\
&\textbackslash\~{}\{\}H & \~{}H & & text mode\\
&\textbackslash textasciitilde & \textasciitilde & & text mode\\Y
&\textbackslash texttildelow & \texttildelow & & text mode\\
&\$\textbackslash tilde\{\textbackslash\ \}\$ &  & $\tilde{\ }$ & math mode\\
&\$\textbackslash sim\$ &  & $\sim$ & math mode\\
&\$\_\textbackslash textrm\{\textbackslash symbol\{126\}\}\$ &  & $_\textrm{\symbol{126}}$ & math mode\\
&aaa\textasciitilde hhhh aaa hhhh & aaa~hhhh aaa hhhh & $aaaa~hhhh aaaa hhhh$\\
\hline
\multirow{5}{*}{\textbar} & \textbar & | & $|$ \\
&\textbackslash textbar & \textbar & & text mode\\
&\$\textbackslash vert\$ & & $\vert$ & math mode\\
&\$\textbackslash mid\$ & & $\mid$ & math mode\\
&\textbackslash\textbar & & $\|$ & math mode\\
\end{tabular}
\end{document}

Output

LaTeX Commands︽

Command︽

The syntax of $\(\LaTeX\)$ command is

\commandname [option1,option2,...]{argument1}{argument2}...

Syntax︽

\commandname

$\(\LaTeX\)$ commands are case sensitive, and have two types of formats.

• Starting with a backslash \ and commandname has a name consisting of letters only. In other words, commandname is terminated by a space, a number or any other non-letter.
• Starting with a backslash \ and commandname has exactly one non-letter. In other words, commandname is terminated after that non-letter.

[option1,option2,...]

Some commands support optional parameters, which are added in square brackets [...] after the commandname.

{argument1}{argument2}...

some commands need an argument, which has to be given between curly braces {...} after the commandname.

Switch︽

A $\(\LaTeX\)$ command applys only to the specified arguments. Most standard $\(\LaTeX\)$ commands have a switch equivalent. Switches have no arguments, but apply on the rest of the scope, in other words the current group or environment. A switch should almost never be called outside of any scope, otherwise it will apply on the rest of the document.

\emph{emphasized text} % a command with argument
{\em emphasized text} % a switch
    

LaTeX Grouping︽

LaTeX Environments︽

Environment is the fundeamental $\(\LaTeX\)$ structural component. Environments form an implicit group to define a block sturcture of a $\(\LaTeX\)$ typeset document. Usually, a special layout is defined for the text inside an environment.

\begin{environmentname}
text ...
\end{environmentname}

Specific environment begins to change after \begin{environmentname} and specific environment will be ended after \end{environmentname} Similar to group, environments must be correctly nested. Besides, environments can also accept arguments.

LaTeX Groups︽

A group is created by putting text within braces, or curly brackets. The most common usage is to group the individual arguments of a $\(\LaTeX\)$ command. In general, $\(\LaTeX\)$ grouping is used to limit the scope of a specific local state by enclosing the part in curly braces. Groups must be correctly nested Control sequences \bgroup and \egroup can also be used to begin and end a group respectively. These control sequences allow to group a part when using braces won't be possible. Besides, pairs of single dollar signs $...$ and double dollar signs $$...$$ that used to delimit math mode are also define groups.

Unit︽

The recognized units recognized by $\(\LaTeX\)$ are

pt  point         (1 in = 72.27 pt)
pc  pica          (1 pc = 12 pt)
in  inch          (1 in = 25.4 mm)
bp  big point     (1 in = 72 bp)
cm  centimetre    (1 cm = 10 mm)
mm  millimetre
dd  didot point   (1157 dd = 1238 pt)
cc  cicero        (1 cc = 12 dd)
sp  scaled point  (65536 sp = 1 pt)

Resources and References︽

• https://www.latex-project.org/help/documentation/usrguide.pdf