\chapterbegin Chapter 2. Book Printing\\versus\\Ordinary Typing


When you first started using a computer terminal, you probably had to adjust
to the difference between the digit `1' and the lower case letter `l'.
When you take the next step to the level of typography that is common in
book publishing, a few more adjustments of the same kind need to be made;
your eyes and your fingers need to learn to make a few more distinctions.


In the first place, there are two kinds of ↑{quotation marks} in books, but
only one kind on the typewriter. Even your computer terminal, which has
more characters than an ordinary typewriter, probably has only a
non-oriented double-quote mark (|"|), because the standard ``ascii'' code
for computers was not invented with book publishing in mind. However, your
terminal probably does have two flavors of single-quote marks, namely `
and '\thinspace; the second of these is useul also as an ↑{apostrophe}.


To produce double-quote marks with \TeX, you simply type two single-quote marks
of the appropriate kind. For example, to get the phrase
$$\displaybox{``I understand.''}$$
(including the quotation marks) you would type
\ttbegin
``I understand.''
\ttend
to your computer.


A typewriter-like style of type will be used throughout this manual to indicate
\TeX\ constructions that you might type on your terminal, so that the
symbols actually typed are readily distinguishable from the output \TeX\ would
produce and from the comments in the manual itself. Here are the symbols to be
used in the examples:
\ttbegin
ABCDEFGHIJKLMNOPQRSTUVWXYZ
abcdefghijklmnopqrstuvwxyz
0123456789"#$%&@*+-=,.:;?!
()<>[]{}`'|up|dn\|vert/_↑~
\ttend
If these are not all on your computer terminal, don't despair; \TeX\ can make
do with the ones you have. An additional symbol
$$\displaybox{\vspace}$$
is also
 used to stand for a {\sl ↑{blank space}}, in case it is important to
emphasize that a blank space is being typed;
thus, what you {\sl really\/} type in the example above is
\ttbegin
``I|vspace|kern0ptunderstand.''
\ttend
Without such  symbol you would have
difficulty seeing the invisible parts of certain constructions, but we
won't be using `\vspace' very often because spaces are usually visible enough.


Another important distinction between book printing and ordinary typing is
the use of ↑{dashes}, ↑{hyphens}, and ↑{minus signs}. In good math books, these
symbols are all different; in fact there are usually at least four different
symbols in use:
$$\linepar\vbox{
a hyphen (-);
an en-dash (--);
an em-dash (---);
a minus sign ($-$).}$$
Hyphens are used for compound words like `daughter-in-law' and `X-rated'.
↑{En-dash}es are used for number ranges like `pages 13--34', and also in
contexts like `exercise 1.2.6--52'. ↑{Em-dash}es are used for punctuation in
sentences---they are what we often call simply dashes. And minus signs are
used in formulas. A conscientious user of \TeX\ will be careful to distinguish
these four usages, and here is how to do it:
$$\linepar\vbox{
for a hyphen, type a hyphen (|-|);
for an en-dash, type two hyphens (|--|);
for an em-dash, type three hyphens (|---|);
for a minus sign, type a hyphen in mathematics mode (|$-$|).}$$
(Mathematics mode occurs between dollar signs; it is discussed later, so you
needn't worry about it now.)


\exercise Explain how to type the following sentence to \TeX: Alice said,
``I always use an en-dash instead of a hyphen when specifying page numbers
like `481--497' in a ↑{bibliography}.''
\answer |Alice said, ``I always use an en-dash instead of a hyphen|\ttspace
|when specifying page numbers like `481--497' in a bibliography.''| \ 
(The wrong answer to this question ends with |'48l-497' in a bibliography."|)


\exercise What do you think happens when you type four hyphens in a row?
\answer You get em-dash and hyphen (----), which looks awful.


If you look closely at most well-printed books, you will find that certain
combinations of letters are treated as a unit. For example, this is true
of the `f' and the `i' of `find'. Such combinations are called {\sl
↑{ligatures}}, and professional typesetters have traditionally been
trained to watch for letter pairs such as |ff|, |fi|, |fl|, |ffi|, and
|ffl|. \ (The reason is that words like `f{}ind' don't look very good in
most styles of type unless a ligature is substituted for the letters that
clash. It's somewhat surprising how often the traditional ligatures appear
in English; other combinations are important in other languages.)


The good news is that you do
{\sl not\/} have to concern yourself with ligatures: \TeX\ is perfectly
capable of handling such things by itself, using the
same mechanism that converts `|--|' into `--'. In fact, \TeX\ will also look
for combinations of adjacent letters (like `|A|' next to `|V|'\thinspace)
that ought to be moved closer together for better appearance; this is
called {\sl ↑{kerning}}.


\medbreak
To summarize this chapter: When using \TeX\ for straight copy, you type
the copy as on an ordinary typewriter, except that you need to be careful
about quotation marks, the number 1, and various kinds of hyphens/dashes.
\TeX\ will automatically take care of other niceties like ligatures and
kerning.


\danger (Are you sure you should be reading this paragraph? The
``↑{dangerous bend}'' sign here is meant to warn you about material that
ought to be skipped on first readng. And maybe also on second reading.)


\danger In case you need to type quotes within quotes, for example a
single quote followed by a double quote, you can't simply type
\thinspace|'''|\thinspace\
because \TeX\ will intrpret this as ''' (namely, double-quote followed by
single-quote).  If you have already read Chapter@5, you might expect that
the solution will be to use grouping---namely, to type something like
\thinspace|{'}''|. But it turns out that this doesn't produce the
desired result, because there is usually less space following a single quote
than there is following a double quot: What you get is {'}'', which is indeed
a single quote followed by a double quote (if you look at it closely enough),
but it looks almost like three equally-spaced single quotes. 
On the other hand, you certainly won't want to type \thinspace|'|\vspace|''|,
because that space is much too large---just as large as the space between
words---and \TeX\ might even start a new line at such a space when making
up a paragraph! The solution is to type \thinspace|'\thinspace''|, which
produces '\thinspace'' as desired.↑(:thinspace)


\dangerexercise OK, now you know how to produce ''' and '\thinspace'';
how do you get ``\thinspace` and `{}``\thinspace?
\answer |``\thinspace`|; and either |`{}``| or |{`}``| or something similar.
(|\thinspace| is also desirable between a single quote and a question mark
or exclamation point.)


\dangerexercise Why do you think the author introduced the control
sequence |\thinspace| to solve the adjacent-quotes problem, instead of
recommending the trickier construction |'$\,$''| (which also works)?
\answer Eliminating ↑{:thinspace} would mean that a user need not learn
the term; but it is not advisable to minimize terminology by ``overloading''
math mode with tricky constructions. For example, a user who wishes to
take advantage of \TeX's ↑{:mathsurround} feature would be thwarted by
non-mathematical uses of dollar signs. \ (Incidentally, neither |\thinspace|
nor ↑{:\,} are built into \TeX; both are defined in terms of more
primitive features, in Appendix@B.)


\chapterend


In modern Wit all printed Trash, is
Set off with num'rous\/\ {\rm Breaks}\raise.5ex\vbox{\hrule width 2em}%
  and\/\ {\rm Dashes}\raise.5ex\vbox{\hrule width 1em}
% no period after the em-dash: stet!
% Sir Walter Scott ruined this quote in his edition of Swift!
\author JONATHAN ↑{SWIFT}, {\sl On Poetry: A Rapsody\/} (1733)
% Rapsody: stet!


\bigskip


Some compositors still object to work
in offices where type-composing machines are introduced.
\author WILLIAM STANLEY ↑{JEVONS}, {\sl Political Economy\/} (1878) % sec 55
% "They are all afraid that if the work is done too easily and rapidly,
% they will not be wanted to do it."
% Jevons goes on to say that justifying and page makeup can't be done
% profitably by machines, so the employees needn't fear losing their jobs.


\eject