Writing texts

Recall from the previous lesson that you write text in the document environment.

Characters

The characters

a-z A-Z 0-9 + = * / ( ) [ ]

and the punctuation marks

, ; . ? ! : ` ' -

and the space, tab and enter can be used directly in LaTeX code for writing text.

\documentclass[a4paper]{article}
\begin{document}
This is a handbook about TeX, a new typesetting system intended for the
creation of beautiful books and especially for books that contain a lot
of mathematics.
\end{document}

Multiple spaces, tabs and line breaks are treated as a single space in LaTeX.

This        looks    like
a normal      sentence  .

However, a blank line creates a new paragraph. We will discuss this later.

The following characters are reserved characters:

$ % ^ & _ { } ~ \

This means they have a special meaning in LaTeX. We already saw how to use {, } and \. If you want to use reserved characters in your text you can use commands:

\# \$ \% \^{} \& \_ \{ \} \~{} \textbackslash{}

When LaTeX encounters a % at a line it will ignore the rest of this line and all whitespace at the beginning of the next line. Hence, % can be used to write comments in your code. For example

\newcommand{\CC}{\mathbf{C}} % This command defines the field C.

Comments are also useful to temporarily remove a piece of text from the output.

Accents and special characters

There are two ways to enter letters with accents like é, ñ and å or special characters: using commands and (sometimes) using your keyboard.

Commands

The first way to enter special characters is by using LaTeX commands. A list of some of these commands is displayed below. (A more extensive list can be found on wikibooks)

Note that we left { } out of these commands (we type \'e instead of \'{e}) since we don’t need these brackets for commands consisting of one non-letter.

Keyboard

On some but not all LaTeX editors you can use special characters by typing them on your keyboard as normal. Not all keyboards of course can type all accented characters, so it is very useful to know the commands for them.

LaTeX distinguishes three different types of dashes in text: the hyphen -, the en dash - and the em dash —. These can be inserted using -, -- and ---. Use an en dash to indicate a range, for example ‘rows 1–10’. Use the em dash to denote a break in a sentence: ‘He was running, Watson—running desperately’. In Dutch it is common to surround the en dash by spaces: ‘Jacqueline vertrok – zonder nog een woord te zeggen’.

An ellipsis is a sequence of three dots indicating that some text is left out. For the right spacing one can use \ldots.

Quotes are typeset with a backtick ` and an apostrophe '.

`quote', ``quote'', ``A `quote' inside a quote''

Paragraphs

Paragraphs can be made in LaTeX by leaving a line blank. For example

\documentclass[a4paper]{article}
\begin{document}

Erd\H{o}s' high productivity can be seen from the fact that he
published around 1500 scientific articles, most of them together with
others. He worked together with about 500 collegues. Erd\H{o}s thought
of mathematical research as a social activity and changed the way of
doing mathematics permanently.

He was engaged with number theory, combinatorics, set theory, analysis
and stochastics, but made contributions to almost every subarea of
mathematics.

In 1984 he won the most lucrative award in mathematics, the Wolf Prize,
and used all but 720 of the USD 50,000 prize money to establish a
scholarship in his parents’ memory in Israel.
\end{document}

By default, LaTeX will justify paragraphs: whitespace is adjusted to spread the words uniformly over the line so that the paragraphs fill the entire width of the page. LaTeX will break words if needed. Every language has its own rules for hyphenation. The correct rules are loaded by the babel package.

Remember also that the default paragraph break in LaTeX is to start a new line, with no empty line in between, and indent this. You can use the package parskip to change this to a new line with an empty line in between and no indentation.

\usepackage[dutch]{babel}
\usepackage{parskip}

Non-breaking space

A non-breaking space is a space which cannot be enlarged and where a sentence won’t break. A non-breaking space (or tie) can be added using ~. One uses this mostly in references:

Chapter~12
Theorem~1.2
Bartel~Leendert van~der~Waerden
Charles~XII
From 0 to~1

“Ties”—denoted by ‘~’ in plain TeX—are the key to successful line breaking. Once you learn how to insert them, you will have graduated from the ranks of ordinary TeXnical typists to the select group of Distinguished TeXnicians. And it’s really not difficult to train yourself to insert occasional ties, almost without thinking, as you type a manuscript. – Donald Knuth

The end of a sentence

LaTeX inserts more whitespace after the end of a sentence than it does between two words. The reason is that this looks good when the text is justified. However, this could cause problems when there is a period in the middle of a sentence; LaTeX thinks the sentence ends and adds more whitespace. To solve this you can use \␣, a backslash followed by a space.

The numbers 2, 3, 5, 7, etc.\ are interesting.

If you want to prevent LaTeX from breaking the line after the period, you can use ~ instead of \␣.

Manual line-breaking

With \- you can manually suggest where to break a line in a word. For example

type\-set\-ting

Here, the line can only be broken at places with a \-. This is useful for words with special characters, since LaTeX doesn’t break these automatically. The same holds for words containing a dash. You should only use this when a word is split incorrectly. Many words will be hyphenated in the right way by the babel package.

Structure

Recall that we prefer to determine the layout of our text by structuring it with commands and environments. We will discuss a few important examples.

Emphasis

Words should be emphasised with the command \emph. Usually emphasised text appears in italics, but this can be changed. It is considered bad practise to use commands like \textit, since LaTeX code is meant for content and not for layout.

This is \emph{important}.
\emph{This is \emph{important}.}

Lists

Lists can be made using the itemize environment and the enumerate environment.

\begin{itemize}
\item Green
\item Yellow
\item Pink
\end{itemize}

In LaTeX it is very easy to number the elements of your list.

\begin{enumerate}
\item Green
\item Yellow
\item Pink
\end{enumerate}

If you want to create lists indexed by letters or Roman numerals instead of numbers, you can load the package enumitem, you can find the documentation for this package here at the LaTeX package database CTAN.

Typesetting text literally

The verbatim environment makes sure text is typeset literally, that is, LaTeX will ignore any commands in the text. The text also gets a monospaced typewriter font so it can be used to typeset computer code:

\begin{verbatim}
def gcd(a,b):
"""
Euclides' algorithm.
"""
while a:
a, b = b%a, a
return b
\end{verbatim}

You can insert a code snippet inline using \verb.

You can set the author with \verb![](\author)!.

The first character after \verb determines where \verb stops. Hence a different character from ! works too.

Hyperlinks

The hyperref package provides the command \url to create hyperlinks. You can load hyperref using

\usepackage[hidelinks]{hyperref}

A hyperlink can be made using

\url{http://www.ctan.org}

or

\href{http://www.ctan.org}{CTAN}

Quotations

There are three standard environments for quotations.

quote

for one or more short quotes

quotation

for longer quotes with several paragraphs

verse

for quotes where line breaking is very important, such as songs. The line has to be broken manually with \\.

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