%-*-tex-*- \ifundefined{writestatus} \input status \relax \fi % \chcode{cont} \def\cqu{\cquote{The life is so short, the craft so long to learn.}{Aphorisms, Hippocrates (460-400~BC)} } \chapterhead{cont}{SPECIAL CHARACTERS\cr and\cr ACCENTS} This chapter discusses {\it special characters}, both those that are single keys (usually) on the terminal but are used for special purposes and those, non mathematics, that end up in the final text as single characters. An example of the first is the |{| used for grouping (see Chapter~\ref{bas} information on {\it grouping}) and an example of the latter is the copyright sign \copyright\ that is obtained by typing |\copyright|. For special mathematics symbols see Chapter~\ref{matsym}. Section~\ref{controluse} discusses the special characters that do not normally print and are used by \tex\ and \intex\ for control purposes. Section~\ref{controlprint} tells how to print them in the text. A second set of special use characters, usually single keys, are really single character commands to \tex\ and \intex. Their behaviour varies depending on the circumstances. In most cases, they can be used with little or no thought. Occasionally errors in use might cause some confusion. For instance, in \intex\ the ``\vrt'' is interpreted as a vertical bar or rule in normal text and mathematics, but as a column separator with a vertical rule while building tables using \intex's |\begintable...\endtable| commands. The complete set of these commands for \intex\ is given in Section~\ref{activechar}. The rest of this chapter discusses the second class of special {\it text} characters, and the means of inserting them in the text. Section~\ref{specialtextsymbols} shows how to obtain such interesting characters as the British Pound ``{\it\$}'' paragraph symbol ``\P''. Quotes, both English ``\dots'' and French {\language = 1 \ldq\dots\rdq} are discussed in Section~\ref{quotes}. Accents on ordinary text letters are in Section~\ref{ordaccent} and on mathematics in Section~\ref{mathaccent}. \shead{controluse}{Control Characters - Meaning} \tex\ and \intex\ have reserved the following control characters for the uses indicated. None of these characters will be actually printed in the text. \bshortcomlist |\|&escape character \dots starts all control and command sequences \cr |{}|&grouping brackets \cr \% &indicates the end of a line in a \TeX\ file. Anything after the \%\ will be ignored by \TeX\ while processing the file. This is used for comments. \cr |\@|&superscript sign\cr |_|&subscript sign\cr |&|&alignment character used to align characters from line to line\cr |$|&\it mathematics mode indicator\cr |$$|&{\it mathematics} mode start and end \cr |$$$$|&{\it display mathematics} mode \dots start and end \cr |#|¶meter indicator for definitions and in alignment preambles\cr |~|&the {\it tie} character \dots\ really an unbreakable space between words. For instance, the space between the initials in D.E. Knuth allows the last name to be split from the initials at the end of the line. The sequence |D.E.~Knuth| will leave the space but not allow the break.\cr \eshortcomlist \shead{controlprint}{Control Characters - Printing} The control characters \begintt { } # $ % & _ \ ~ ^ \endtt \ls are obtained by the control sequences \begintt $\{$ $\}$ \# \$ \% \& \_ $\backslash$ \^{ } \~{ } \endtt \ls respectively, except as accents. The last two are actually obtained by ``accenting'' a space. In mathematics the ``~\^{ }~'' and the ``~\~{ }~'' must be obtained using the mathematic accents (see Section~\ref{mathaccent}) as |\hat{ }| or |\tilde{ }|. The net effect of this is that all characters are available in any mode. \shead{activechar}{\intex\ Special Characters} \intex\ special characters are all active --- meaning that they are single character control sequences. The complete list is given below. They are used for specifying column separators in tables. \bshortcomlist \vrt&this is a \vrt\ in normal text, a \vrt\ {\it Rel} in mathematics (see Chapter~\ref{matsym}). While making a table inside \intex\ |\begintable ... \endtable|, the \vrt\ is a vertical rule or line column that is used to separate data columns and {\bf must not be used in mathematics inside tables -- use |\vrt|} (see Chapter~\ref{align}).\cr |"|&the double quote should not be used in ordinary text. \intex\ will give you a gentle reminder to either |``| or |''|. It will then put the " in the text. The |"| is used while making tables for indicating a rule column where the rule is omitted.\cr \eshortcomlist \shead{specialtextsymbols}{Special Text Symbols} \tex\ supplies a number of special symbols that can be used in ordinary text, and some admonitions about those that should not. There are three kinds of dashes in normal typeset material and \tex\ supplies all three. They are - -- --- and are produced by |-| |--| and |---| respectively. They are known officially as the {\it dash, endash,} and {\it emdash}. They are used as hyphens, word separators, and idea separators, respectively. These are recognized by \tex\ as {\it ligatures}. Although the English ligatures such as ``ff'' and ``ffi'' are recognized by \tex, most in other languages are not.\footnote{\dagger}{However, it is easy to modify \tex\ so that it does recognize those ligatures. Meanwhile, it is necessary to live with the mechanism given.} These require special symbols. In addition there are special symbols such as \copyright\ and \dots\ that are also useful. Here is a list supplied by {\it plain} \bshortcomlist \@|\aa, \AA|& the \aa\ and \AA \cr \@|\ae, \AE|& the ligature \ae\ or \AE \cr \@|\copyright|&the copyright symbol \copyright \cr \@|\dag|& the dagger \dag. The math mode |$\dagger$| looks similar but incorporates the spacing of a binary operator. \cr \@|\ddag|& the double dagger \ddag. The math mode |$\ddagger$| looks similar but incorporates the spacing of a binary operator. \cr |\dots|&dots in text \dots\ like so \cr \@|{\it\$}|&the nonobvious British Pound {\it\$} \cr %indexing problem with $ \@|{\it\&}|&the script ampersand {\it\&} \cr \@|\i|&the dotless \i\ for use in \^\i \cr \@|\j|&the dotless \j\ for use in \^\j \cr \@|\l, \L|&the \l\ and \L \cr \@|\o, \O|&the \o\ and \O \cr \@|\oe, \OE|&the ligature \oe\ or \OE \cr \@|\P|&the paragraph symbol \P \cr \@|\S|&the section symbol \S \cr \@|\ss|&the \ss \cr \eshortcomlist \shead{quotes}{Opening and Closing Quotes} The ``double quote'', |"| on the keyboard {\bf should not be used}, except in its accent form |\"| to be described later in Section~{\ref{ordaccent}} on accents. For the |\englishversion| of \intex, opening {\bf double} quotes may be obtained either with the |``| in plain or using |\ldq|. The closing {\bf double} quotes may be obtained similarly using the |''| or the |\rdq|. When |\versionfrancaise| is in force, |\ldq| and |\rdq| when used like so |\ldq guillemets\rdq|\footnote{\ddagger}{This is the best we can do with the present fonts} will give {\language=1 \ldq guillemets\rdq}. Note that the |\rdq| is an ordinary command that will delete spaces following it. \shead{ordaccent}{Ordinary Accents} The ordinary accents supplied in {\it plain} are for the occasional insertion of a foreign language in English text. The mechanisms are complete, and the accents are quite well placed, but the method of obtaining them from keyboards with special characters is not built in. In \tex, the accent always precedes the letter accented. Thus |\'ecole| gives \'ecole, and |fran\c cais| gives fran\c cais. Note the annoying space after the |\c| in the word. This form of input reduces the readability of the text. Agreement is needed to obtain a consistent multi-language format. The following is a list of the ordinary accents in \tex\ specified by {\it plain}. \bshortcomlist |\`|&accent grave as in \`a\cr |\'|&accent acute as in \'e \cr |\^|&circumflex or ``hat'' as in \^o \cr |\"|¨aut as in \"o \cr |\~|&tilde as in \~n \cr |\=|&long vowel as in \=o \cr |\.|&dot accent as in \.a \cr |\b|\]||&accent bar-under as in \b d, note space \] \cr |\c|\]||&accent cedilla as in \c c, note space \] \cr |\d|\]||&accent dot-under as in \d o, note space \] \cr |\u|\]||&accent breve as in \u o, note space \] \cr |\v|\]||&``check'' as in \v o \cr |\H|\]||&long Hungarian umlaut as in \H o\cr |\t|\]||&tie-after accent as in \t ao\cr \eshortcomlist \shead{mathaccent}{Accents on Mathematical Symbols} Placing accents on mathematical symbols requires a certain amount of care. {\it Plain} \tex\ gives an extra set of commands that are to be used for characters in mathematics mode. All of the following should be used when in mathematics mode. Note the required space \], in almost all cases. \begingroup \descrwd=2in \bshortcomlist |'|& the prime as in $x'$ \cr |''|& the double prime as in $x''$ \cr |\acute|\]||&as in $\acute x$ \cr |\bar|\]||&as in $\bar x$ \cr |\breve|\]||&as in $\breve x$ \cr |\check|\]||&as in $\check x$ \cr |\dot|\]||&as in $\dot x$ \cr |\ddot|\]||&as in $\ddot x$ \cr |\grave|\]||&as in $\grave x$\cr |\hat|\]||&as in $\hat x$ \cr |\tilde|\]||&as in $\tilde x$ \cr |\vec|\]||&as in $\vec x$ \cr |\widehat|\]|[][]|& as in $\widehat{x},\widehat{xy}, \widehat{xyz}$\cr |\widetilde|\]|[][]|& as in $\widetilde{x},\widetilde{xy}, \widetilde{xyz}$\cr \eshortcomlist \endgroup When using these in a technical paper or report, it is probably better to make a short definition for the accented character. This will reduce typing and facilitate the changing the style {\t consistently} throughout the paper. It is a very simple form of {generic typesetting}. \ejectpage \done