\chapter{More things you should know}
%\addtocontents{toc}{sleeve}
\section{Changing font}
Once desktop publishing arrived\footnote{Desktop publishing arrived
  long before Paul Brainerd of Aldus invented the term and Apple
  created the bandwagon. Xerox \textsc{Parc} had been doing all that
  about 1978 with the Bravo system -- even to the extent of on-demand
  immediate laser printing. \TeX\ users throughout the known world had
  been publishing via their desktop terminals, and the \textsc{Unix}
  world had also been using the \texttt{nroff}\slash \texttt{troff}
  family and its pre-processors. The key to success is marketing.}
people expected to change font\index{fonts} at the drop of a hat.
Brought up on typewriters, with no typographic knowledge at all, they
suddenly acquired a whole new vocabulary of `Palatino', `Bookman',
`Zapf Chancery', and strongly held opinions about kerning,
letterspacing, serifs, tracking and other arcane typographical subjects
(rational views may be found in~\cite{RM80} and~\cite{PL92}).

\section{Some history (again)}
When Knuth designed \TeX, he also designed fonts to go with it. Or
rather, he used an existing typeface, Monotype's Modern 8A, and
produced what he termed `Computer Modern'. He had some help, but
basically this `family' is the suite of fonts with which \TeX\ (and
\LaTeX) were initially tuned. That is not to say you cannot use
others, just that some work \emph{may} be needed before it will be a
success. The Computer Modern family comprises about 75 `different'
fonts. Most families comprise three or four different fonts -- medium,
bold, italic and so on. Now, 75 fonts does not mean that they are all
strikingly and immediately different: Knuth took the notion of a
`design size' rather seriously. What this means is that the font is
designed to be displayed and read at a specific size. Thus we have
several versions of Computer Modern\index{Computer Modern} Roman,
designed to be read at 5, 6, 7, 8, 9, 10, 12, 17 and 25
points~\cite{DEK-cm}. These are genuinely different: the proportions
change subtly as we change size.

Contemporary digital fonts tend to be stored as `outline' information, where to
arrive at a particular size, we `merely' magnify the `prototype' outline. This
will not change the outline, just the size. Adobe encoded `hints' into their
\PS\ `Type~1' outlines, which help  preserve the subtle changes. 
MicroSoft's `TrueType' fonts contain similar hints -- but distinct enough
to avoid legal action. However, these hints have as much to do with
accommodating digital fonts to the various resolutions at which they may be
displayed as to modifying them for the point size at which they are
displayed. 

Returning to the Computer Modern fonts, they are usually stored as
`rather compressed' bit maps, for a given resolution. Thus a laser
printer would typically require resolutions of 300\,dpi or 600\,dpi,
and a phototypesetter perhaps 1270\,dpi. Outline fonts clearly have an
advantage here, since you would only need one font to be stored, The
rasterization of an outline takes place at print time, in the
printer's own processor. At the time, Knuth's solution seemed a good
one. It certainly assured quality, but it does require a lot of
storage space for all those bit maps. But disk space is cheap. And if
you can store the bit maps down on your laser printer or
phototypesetter, the data transmission times can be reduced. If you
are working on a network, you may have to store the bit maps on a
server, where you then have the time consuming business of shipping
them down to the printer.

If we delve a little more into the process, we discover that Knuth
also created a `language' to describe fonts -- \MF~\cite{DEK86}. The
descriptions of Computer Modern are encoded in \MF\ (see, for
example~\cite{DEK-cm}). Some implementations of \LaTeX\ will include
\MF, and you may find that when you need particular fonts, they are
generated on the fly. Typically, you will take many years to require
all the Computer Modern fonts at all the sizes possible, and you can
afford to accumulate them over time, \MF\ generating them as required.
Since some of these fonts may only ever be required in rather
exceptional and infrequent circumstances, a common strategy is to
delete the less well used ones after use.  Given the current processor
speed commonly available, this is quite a sound approach. But it does
depend on you having a suitably configured system where all these
various components can inter-communicate.

Equally, Postscript and Truetype versions of the Computer Modern fonts are now
generally available, both commercially and within the public domain.

For many years \TeX\ and \LaTeX\ gained a reputation of working with
only Computer Modern and unfortunately, some people, especially
publishers, did not like Computer Modern, usually preferring Times. The
reputation was unfounded, but it stemmed from two main origins:
firstly, it did take some time and effort (and sometime access to
proprietary information) to utilise other fonts; and secondly, other
fonts did not necessarily have the full range of characters which were
readily available for Computer Modern. Eventually the problem was
solved quite comprehensively by Frank Mittelbach and Rainer Sch{\"o}pf
with the introduction of the `New Font Selection Scheme'~\cite{FM89}
or \textsf{NFSS}.  Although we will look at this later, if you are
anxious to eschew the use of good old Computer Modern for your
particular favourite, consult Chapter~7 of the \textsl{Companion}.

\section{What fonts do we have?}
We won't actually use all the fonts\index{fonts} here, but just look
at the ones we get by default with \LaTeX.\footnote{These notes were
  originally written with the intention that the font used would be
  Computer Modern. The house style of this august organ is
  Baskerville. If the \textsf{NFSS} transformations have been done
  correctly, all should be well.} Depending how you count, there are
eleven types or `styles' of font available, divided into three
independent groups: the `family' group is Roman, Sans Serif and
Typewriter: the `series' group comprises Medium and Bold: while the
`shape' group is Upright, Italic, Slanted and Small Capitals. That
leaves one orphan, Normal.  Normal is the style used in the `body' of
the text. But even then that only comes to ten. The eleventh is an
`emphasis' style.  The results of using emphasis is to change the
appearance in some way. Note that we do not use underlining at all --
that is a typing convention for emphasis which is
\underline{never}\footnote{hardly ever} used in typesetting. We are in
the Gutenberg tradition, not the Sholes tradition. Table~\ref{tfonts}
shows what these fonts look like on the page. If you look closely you
will note that there appears to be no difference between Upright,
Medium, Roman and Normal.  At this stage, this is true; later we shall
see the distinctions in more detail.
\begin{question}
  Sholes who? By now, very few people have direct experience of having
  used a typewriter. For those who do, what other leftovers from the
  days of the typewriter afflict us? Many word processing packages
  defer to typewriting practise and may provide hints and clues. Is it
  necessary to ask who Gutenberg was? or Caxton? or the cutely named
  Wynkyn de Worde? or even Baskerville?
\end{question}
\begin{table*}
\begin{center}
\begin{tabular}{|llp{3in}|}
\hline
Style & instruction & example \\
\hline
Roman &\verb|\textrm| &\textrm{The quick brown fox comes to the
aid of the Hamburgerfons} \\Upright &\verb|\textup| &\textup{The quick brown fox comes to the aid of the
Hamburgerfons} \\ 
Sans Serif &\verb|\textsf| &\textsf{The quick brown fox comes to the aid of
the Hamburgerfons}\\ 
Typewriter &\verb|\texttt| &\texttt{The quick brown fox comes to the aid of
the Hamburgerfons}\\
Medium &\verb|\textmd| &\textmd{The quick brown fox comes to the aid of the
Hamburgerfons} \\ 
Bold & \verb|\textbf|&\textbf{The quick brown fox comes to the aid of the
Hamburgerfons}\\ 
Upright & \verb|\textup|&\textup{The quick brown fox comes to the
aid of the Hamburgerfons}\\
Italic & \verb|\textit|&\textit{The quick brown fox comes to the
aid of the Hamburgerfons}\\ 
Slanted &\verb|\textsl| &\textsl{The quick brown fox comes to the aid of the
Hamburgerfons}\\  
Small Capitals & \verb|\textsc|&\textsc{The quick brown fox comes to the
aid of the Hamburgerfons}\\  
Normal &\verb|\textnormal| &\textnormal{The quick brown fox comes to the aid of
the Hamburgerfons}\\ 
\hline
\end{tabular}
\end{center}
\caption{font styles\index{fonts} readily available}\label{tfonts}
\end{table*}

To change the type `style', we use the simple, fairly mnemonic instruction given
in Table~\ref{tfonts}. \LaTeX\ has a very powerful technique available
which makes life easy -- grouping. Grouping is a notion central to the
whole existence of \LaTeX. We have already met some sorts of grouping,
where we have a \verb|\begin| and \verb|\end|. There is a simpler
grouping\index{grouping} -- \verb|{| and \verb|}|. If we, for example
say
\begin{verbatim}
The  song really \emph{is} \textit{A-Sitting 
On A Gate}: and the tune's my own invention.
\end{verbatim}
the parts enclosed in braces are the parts which will be emphasised (by
\verb!\emph!), or turned into italics (by \verb!\textit!). The remainder of the
passage will use whatever happens to be the font already in use.  The word
\verb|is| is really `emphasised'\index{emphasis}, while the \verb|A-Sitting On A Gate| part is
a title (of sorts -- see Table~\ref{talice}). We may wish all such titles to be
represented in a particular font or style, to assist readers distinguish
this sort of information. 

It is a good idea to review the reasoning behind changing font:
presumably it is to provide the reader with visual clues to the
structure of the contents of the document. Thus headings are usually
in a different font from the text, and different levels of heading
usually have slightly different characteristics: quoted text is often
presented in a different font, and so too is emphasised material.
Given that human perception seems to work best with $7\pm2$ discrete
items at a time, you can see that you probably do not want too many
different fonts at a time.
\begin{table*}
\begin{center}
\small
\begin{tabular}{|ll|}
\hline
what the name of the song is called& Haddocks' Eyes \\
what the name is & The Aged Aged Man\\
what the song is called & Ways and Means\\
what the song really {\em is} & A-sitting On A Gate\\
the tune & I give thee all, I can no more\\
\hline
\end{tabular}
\end{center}
\caption{Carrolliginian confusion -- totally irrelevant here}\label{talice}
\end{table*}

At last, this brings in the use of emphasis: \LaTeX\ uses the instruction
\verb|\emph|\index{emph@\texttt{emph}} to denote emphasis. Let's look again at
the last example to see that
\begin{verbatim}
The  song really \emph{is} \textit{A-Sitting 
On A Gate}: and the tune's my own invention.
\end{verbatim}
gives
\begin{quote}
The  song really \emph{is} \textit{A-Sitting 
On A Gate}: and the tune's my own invention.
\end{quote}
Here we have distinguished the two elements `emphasised text' and
`italicized text'. In this circumstance, it is hardly visible, except in the
marked up text. But let's change things a bit:
\begin{verbatim}
\textit{The  song really \emph{is} \textit{A-Sitting On A Gate}: 
and the tune's my own invention.}
\end{verbatim}
This time we  find that the
emphasised text is in the roman font:
\begin{quote}
\textit{The  song really \emph{is} \textit{A-Sitting On A Gate}: 
and the tune's my own invention.}
\end{quote}
\LaTeX\ is smart enough to do that, but unfortunately is not smart
enough to change the title information. After all, you have specified
that it is italicised. The fact that you then repeat the italicisation
instruction changes nothing, although you may have wished that the
second \verb+\textit+ instruction changes to some different font so
that that part looks different. Nevertheless, this can be a useful
feature. Do not think of `emphasis'\index{emphasis} as simply
`italics', because that is not what it means. It is a function which
may be implemented in a variety of ways, depending on the
circumstances.

\begin{question}
Take some of the earlier text material and change fonts, either over the
whole document, or just selected parts. Which fonts do you find easier to
read? Are the fonts which are easier to read on the screen also the fonts
which are easier to read on paper?
\end{question}

\section{Bigger or smaller}
You will have observed that fonts are available in more than one size.
\LaTeX\ has a series of instructions which allow you to change the
size of any font, very easily. The instructions used are given in
Table~\ref{tsize}. Their exact behaviour depends on the options you
have set up. The order of the sequence remains constant, but sometimes
two adjacent `sizes' may use the same sized font (without telling
you).
\begin{table*}
\begin{center}
\begin{tabular}{|ll|}
\hline
size&style\\
\hline
\verb|\tiny| & \tiny Aa\\
\verb|\scriptsize| & \scriptsize Aa\\
\verb|\footnotesize| & \footnotesize Aa\\
\verb|\small| & \small Aa\\
\verb|\normalsize| & \normalsize Aa\\
\verb|\large| & \large Aa\\
\verb|\Large| & \Large Aa\\
\verb|\LARGE| & \LARGE Aa\\
\verb|\huge| & \huge Aa\\
\verb|\Huge| & \Huge Aa\\
\hline
\end{tabular}
\end{center}
\caption{the sizes\index{size} available}\label{tsize}
\end{table*}
The immediate question is `are all these sizes available for all the
fonts?'

\begin{question}
Are all these sizes available for all the fonts? Remember to try the
different size options as well as the different fonts.
\end{question}

The way that these size-changing instructions are used is quite different
from the font-changing instructions. A font changing instruction looks like
\verb+\textrm{text}+, while to change size you say \verb+{\small text}+.
This difference is quite crucial. The size changing merely indicates a new
condition which is operational until the end of the group in which it
occurs. We could, for example, say
\begin{verbatim}
\Huge Come, \huge I'll \LARGE take \Large no 
\large denial, \normalsize  we must 
\small have a \tiny trial
\end{verbatim}
and each change in size would take place when the instruction occurs in the
text:
\begin{quote}
\Huge Come, \huge I'll \LARGE take \Large no \large denial,
\normalsize  we must \small have a \tiny trial
\end{quote}
 We might be advised to enclose the whole thing in braces, lest any
succeeding text was also placed in the \verb+\tiny+ size of font. If the
size changes are not grouped, separating them out, they remain in effect.

This different style of usage harks back to the older form of
\LaTeX\index{latex!latex2.09@\protect{\LaTeX\,2.09}}. It should not
cause too much confusion, since you would not normally want to change
size in your text. Any such size changes should be restricted to
special conditions, like section headings or new environments, which
you would not be writing as you go along, but would have been defined
separately.  Later we may see how to do these.


\section{Accumulation}
It may come as a pleasant surprise to realise that it is possible to
combine the font changing and the size changing mechanisms, and that
something sensible happens. For example, 
\begin{verbatim}
a \textsf{\Large mouses's} \textit{\tiny tail} 
\end{verbatim}
will result in `a \textsf{\large mouses's}
\textit{\tiny tail}', which is presumably the effect we wished.                                         

Sometimes fonts are not available in all sizes: had you written
\begin{verbatim}
a \textsl{\large mouses's} \textsc{\tiny tail} 
\end{verbatim}
you may find there is no \verb|\tiny| small capitals font
available. \LaTeX\ will substitute something else -- and does so
without telling you. To some extent this lack of a suitable font is
implementation dependent, since it can be possible to create or obtain the
`correct' font for use in this situation. In the current conditions it would
yield:
\begin{quote}
a \textsl{mouse's} {\tiny \textsc{tail}}
\end{quote} 

Do note that these size changing instructions are absolute, not
relative. Saying something like
\begin{verbatim}
a {\small mouses's {\small tail}} 
\end{verbatim}
will not make the tail even smaller. In passing, note that if there is
any chance of the text appearing on more than one line, it would be
best to end a paragraph (by inserting a blank line) before the closing
\verb+}+ or else you may get small text on the existing line spacing.
Or if you were using \verb|\large|, the even worse case of large text
on the existing line spacing, with ungainly and uneven line spacing as
\LaTeX\ moves things around to fit. But you really ought not to
be changing size as you go along like this. The examples here are hardly 
the stuff of the normal article, report or book.

In the previous example, we would not be able to obtain a slanted small capital
font by
\begin{verbatim}
a \textsl{mouse's {\tiny \textsc{tail}}}
\end{verbatim}
But if we return to our description of fonts in three groups, a family, a series
and a shape, we will find that these three are truly indpendent. That is to say I
can ask for a bold sans serif \textbf{\textsf{mouse's tail}} by
\begin{verbatim}
\textbf{\textsf{mouse's tail}}
\end{verbatim}
or for a typewriter medium small caps \texttt{\textmd\textsc{{mouse's tail}}} by
\begin{verbatim}
\texttt{\textmd\textsc{{mouse's tail}}}
\end{verbatim}
This is an example that fails in the current font set up. 
If you examine the log file closely enough, you will find
that you have been told, and also told what substitute has been chosen.
This is a topic we'll look at in more detail later.

In principle, you may combine any family with any series with any shape and
expect to see something sensible.
\begin{question}
Try some of these combinations. How would you make the mouse's tail {\small
progressively
\scriptsize smaller}?
\end{question}

\section{Accenting the positive}
Now it is time for something even more frivolous. One of the nice
features of \LaTeX\ (although of marginal real use in English), is its
excellent support of diacritical\index{diacriticals} marks and foreign
letters. Naturally there is an ulterior motive for introducing these
now.
     
First the special letters. \LaTeX\ recognises instructions for the
diphthongs\index{diphthongs} \OE, \AE, \oe\ and \ae\ (commonly used in
Latin and in some Scandinavian languages, among others). It also
recognises the German `\ss' (ess-zet) symbol. It will handle the \AA,
\aa, \O\ and \o\ of some Scandinavian languages.  And lastly, it copes
with the Polish suppressed-L, \L\ and \l.
     
How do we get these into our text?   Follow the \verb+\+
by a special instruction as shown in Table~\ref{tnatchar}.
\begin{table*}
\begin{center}
\begin{tabular}{|cl|}
\hline
instruction&explanation\\
\hline
\verb|\ss| & gives the German \ss \\
\verb|\OE| & gives the \OE\ diphthong \\
\verb|\oe| & gives the \oe\ diphthong \\
\verb|\AE| & gives the \AE\ diphthong \\
\verb|\ae| &  gives the \ae\ diphthong \\
\verb|\O|  & gives the letter \O\ \\
\verb|\o|  & gives the letter \o\ \\
\verb|\AA|  & gives the letter \AA\ \\     
\verb|\aa|  & gives the letter \aa\ \\
\verb|\L|   & gives the letter \L \\
\verb|\l|   & gives the letter \l\ \\
\hline
\verb|?`|  & gives the symbol ?` \\
\verb|!`|  & gives the symbol !` \\
\hline
\end{tabular}
\end{center}
\caption{the so-called `national'\index{national characters}
characters}\label{tnatchar}
\end{table*}
How do you use these new instructions? The `recommended' way for beginning
\LaTeX-users is to enclose them in braces\index{braces}. This never fails. Thus
to write \OE dipus in \LaTeX, you actually write
\verb|{\OE}dipus|.
 This helps to distinguish \verb|{\OE}dipus| from \verb|\OEdipus|, which
\LaTeX\  would assume was a new (probably unknown) instruction.


There is another, briefer,  way, which you will encounter frequently: leave
a blank space between the instruction and the rest of the word
\begin{verbatim}
\OE dipus
\end{verbatim}
Note that in this form any extra spaces between
\verb|\OE| and
\verb|dipus|  will be ignored, as far as creating the output is concerned.
Since all extra spaces are ignored, leaving a few extra, or even writing 
\begin{verbatim}
\OE 
dipus
\end{verbatim}
will not leave a space between the diphthong and the rest of the word
which follows when the passage is set. In other words, a line break (a `carriage
control') is just another space to \LaTeX. This gobbling up of extra
blanks\index{space} is a normal feature of \LaTeX. If we group\index{grouping}
the instruction,  there is no need to follow it by a space, and in fact 
\verb|{\OE} dipus| will give the result `\OE{} dipus', which is not what was
required. 
     
\begin{question}
In what ways are the following different?
\begin{verbatim}
{\OE }dipus, {\OE} dipus, \OE {dipus}, 
\O{E}dipus
\end{verbatim}
And what other `useful' possibilities are there?
\end{question}  
What implication does this shorthand method have for instructions which come at
the end of words? Consider trying to write:
\begin{verbatim}
the Schlo\ss of the Rhine valley
\end{verbatim}
The word `Schlo\ss' would appear as we
require, but the spaces which follow would be ignored,
and the next word would begin immediately after the \ss. This is
generally not what we want. In order to solve this problem, there are a
variety of solutions. We could have used \verb+{\ss}+ (the grouped
instruction), as  recommended, or we can use a new instruction, \verb*|\ |, that
is, the backslash followed by a space, which introduces  a `command
space'\index{space} (or a `control space' or even a
`hard space'). Thus what we probably wanted was  
\begin{verbatim}
the Schlo\ss\ of the Rhine valley
\end{verbatim}

In this approach, the `hard space' lets \LaTeX\ know where
the instruction ends. If you look at this more closely,
you will realise that there are other ways to signify
the end of a instruction. One of them was illustrated
with the \verb|{\OE}dipus| sequence. There the \verb|}| was able
to indicate the end of the instruction. Actually,  \verb|\OE{}dipus| would have
had the same effect. The sequence \verb|{}| looks odd, and seems to mean
nothing, but from time to time, even nothing has its uses. In the
alternative shown with the \verb*|Schlo\ss\ | sequence, the occurrence
of a \verb|\| `obviously' begins a new instruction, and therefore indicates the
end of the previous one.

There is an advantage to using the shorthand, which is not readily
apparent: the kerning information is used. Once we group the instructions, the
kerns\index{kern} between characters are ignored. While it is unlikely that you
will notice this in many situations (especially if you are not familiar with
French or German typography), it is perhaps an encouragement to use
the shorthand. There is always some pleasure to gained from the feeling
that you are somehow doing things `right'.

In Table~\ref{tnatchar} the two `inverted' symbols were included as a sort of
national character. These are a little odd, and have been known to cause
confusion from time to time. If you are  careless where you type 
spaces and confuse your opening and closing quotes, 
you could end up with something like this dreadfully forced example:
\begin{verbatim}
....oh no!`he said quite emphatically....
\end{verbatim}
 These two national
characters need not be enclosed in braces, since they are not standard \LaTeX\
instructions, in the sense that they do not begin with the backslash. They
work rather differently. On the other hand, feel free to put 
braces in if you want. Nothing untoward will occur.

\LaTeX\  also has lots of diacriticals\index{diacriticals} (Lamport refers to
them as accents\index{accents|see{diacriticals}}, but some are not). The list is
given in Table~\ref{tdiacrit}.
\begin{table*}
\begin{center}
\begin{tabular}{|cll|}
\hline
\verb|\`| & grave  & \verb|\`{e}| gives \`e \\
\verb|\'| & acute or aigu & \verb|\'{e}| gives \'e  \\
\verb|\^| & circumflex or hat & \verb|\^{o}| gives \^o \\
\verb|\v| & inverted circumflex (h\'a\v cek accent) & \verb|\v{c}| gives \v c
\\ 
\verb|\u| & breve & \verb|\u{o}| gives \u o \\
\verb|\=| & macron, long vowel &\verb|\={u}| gives \= u \\
\verb|\"| & umlaut or dieresis & \verb|\"{u}| gives \" u \\
\verb|\H| & Hungarian umlaut & \verb|\H{o}| gives \H o \\
\verb|\~| & tilde & \verb|\~{n}| gives \~{n}\\
\verb|\.| & dot accent & \verb|\.{y}| gives \.y \\
\verb|\t| & tie & \verb|\t{oo}| gives \t{oo}\\
\verb|\c| & cedilla & \verb|\c{c}| gives \c c \\
\verb|\d| & dot under & \verb|\d{d}| gives \d d \\
\verb|\b| & bar under & \verb|\b{a}| gives \b a \\
%\verb|\r| & circle over (ring) & \verb|\r{u}| gives \r{u} \\
\hline
\multicolumn{3}{l}{and although not diacriticals, we should mention}\\
\hline
\verb|\i| & dotless i & \verb|\i| gives \i\\
\verb|\j| & dotless j & \verb|\j|  gives \j \\
\hline
\end{tabular}
\end{center}
\caption{the diacriticals\index{diacriticals}}\label{tdiacrit}
\end{table*}     
By and large, the instructions are fairly logically named.
     
     
In order to get accents over i and j, you really ought to take the dot
off first. \LaTeX\  supports a dotless i and j, provided by \verb|\i| and
\verb|\j|. These allow you to do things like \^{\i} (from \verb|\^{\i}|), or even
\t\i\j, (from \verb:\t{\i\j}:), should you ever find a reason to do so.
     
The general rule with all these sequences is -- accent first, then letter.
At first this sounds counter intuitive, after all, we say `e-acute',
or  `o-circumflex'.

None of these accents are really `fundamental' to \LaTeX, in the sense that
they are all created in much the same way, a way that is accessible.    If we
knew enough we could even create our own diacriticals. For example, Polish has a
\r{u} character, where the `ring' can be defined as a diacritical symbol. 

\begin{question}
In order to demonstrate your skills with these fancy fripperies, try
setting some of the following:

\begin{quote}
\upshape
Hs\"an Tsang, Tath\=agata, \'S\=akyamuni, Vai\'sravana;
Pi-ma-w\^en, Li Y\"uan-chi, \=Ananda K\' a\'syapa,
Manju\'sr\=\i;
V\"ain\"am\"oinen, \"Aij\"o, V\"olusp\'a;
Anne Bront\"e, Honor\'e de Balzac, Fran\c cois Rabelais;
na\"\i ve, r\'egime, fa\c cade, man\oe uvre, encyclop\ae dia;
\AE gean Sea, Ch\^ateau d'If, Gda\'nsk, \"O\H o\c z, N\^\i mes.
\end{quote}
\begin{quotation}
\upshape
Zde se v\v semo\v zn\v e sna\v z\'\i\ m\v e p\v
reluvit, abych  je\v st\v e n\v ekolik
m\v es\'\i  a napsal je\v st\v e jednu
oper\.{u}. Hay\i r! \.I\c s \"oyle de\u gil. B\"uy\"u\u g\"u
k\"u\c c\"u\u g\"une takilmay\i\ pek severdi. Ce f\^ut
d'ores et d\'ej\`a une id\'ee d\'eg\'en\'er\'ee et
ambig\"ue. 
\end{quotation}
\end{question}

If you were normally writing in a language which made use of diacritical
marks or national characters, you would find this all rather tedious. You
would likely have a keyboard which had characters like (for example) \'e,
\aa, \ss, and so on. Having to insert the special \LaTeX\ sequences would,
at the very least, be error-prone. It is possible to tailor \LaTeX\ to take
account of this, so that when you type the single character \'e, \LaTeX\
interprets it correctly. Later we'll look at some \LaTeX\ `packages' which
simplify this task.
There should be added benefits, since it will ensure that
the kerning information is also handled correctly; and the
hyphenation\index{hyphen}\index{hyphenation} should also be
correct for the language you are using.

The default `language', which \LaTeX\ assumes it is using is American
English. Not only does this mean that other languages are hyphenated in a rather
haphazard way, it also results in words with diacriticals generated through
the instructions of Table~\ref{tdiacrit}
being hyphenated even less well (no hyphenation after the first
diacritic). This is a deliberate gloss which does not quite tell the truth.
We'll revisit this topic later.

\section{Hy-phen-a-tion}
\LaTeX\ chooses hyphenation points by a hybrid method. It uses an algorithmic
technique which is supplemented by a small dictionary of `exceptions'. The
algorithm it uses can be taught to recognise the appropriate hyphenation
points for other languages (see Appendix~H of~\cite{DEK84}). A large number 
of alternatives have been
collected or developed by Johannes Braams~\cite{JB91} and are available as a
`package' to \LaTeX\ users. If you really have to hyphenate German, or
Esperanto, or even English now, refer to Chapter~9 of the \textsl{Companion}. 

You can hyphenate words yourself as they
occur,  by inserting a special command which
indicates a \emph{potential} or \emph{discretionary}. For example, in
\verb|Tyr\-rhenian| the \verb|\-| indicates a  discretionary hyphen.
Note that this instruction is not  followed by a space. 
Declaring each potential hyphenation is tedious, and one alternative is to
declare the potential hyphenations as:  
\begin{verbatim}
\hyphenation{Tyr-rhenian manu-script manu-scripts}
\end{verbatim}
That is, simply a list of hyphenated words, separated
by spaces. This has a global effect, since what happens here is
that these words are added (temporarily) to \LaTeX's `exception
dictionary'. As noted above, \TeX/\LaTeX{} hyphenates by algorithm,
but there is a small dictionary of exceptions. The best place for
this hyphenation instruction is in the preamble.

Note that \LaTeX\ will not realize that \verb|manu-scripts| is merely a
regularly formed plural of \verb|manuscript|. Similarly, this
mechanism can know nothing about any other regularly formed
inflections. On the other hand, the standard hyphenation can cope
with many inflections. Explicitly declaring
hyphenation points will not help words which already contain
hyphens. While \mbox{`pricking'} by itself can be hyphenated to
\mbox{`prick-ing'}, `\mbox{pin-pricking'} is not hyphenated to \mbox{`pin-prick-ing}'.
If we were to say  
\begin{verbatim} 
\hyphenation{pin-prick-ing} 
\end{verbatim} 
we could easily end up with \mbox{`pinpricking'}. In this case we would
have to use \verb|pin-prick\-ing| throughout the document. 
\begin{question}
One way to see the effect of hyphenation is to reduce the number of words per line.
The easiest way you know so far is to use a large font size, or to use
the \verb+twocolumn+ option. Choose some text and do so.
\end{question}



