%-*-tex-*- \ifundefined{writestatus} \input status \relax \fi % \chcode{shead} \def\cqu{\cquote{The chief virtue that language can have is clearness, and nothing detracts from it so much as the use of unfamiliar words.}{On the Natural Faculties, Galen } } \chapterhead{shead}{CHAPTER\cr and SECTION\cr HEADS} \intex\ supplies commands for creating chapter and section heads. The default style of the heads are those given in this book. They form the basis of the style that naturally results from the use of \intex. Some changes in style such as the fonts used are quite easy; others require more care. This chapter introduces the commands for creating section heads, whether they occur during the initial part of the document or within appendices. All of the commands have the same format with or without autonumbering or automatic generation of table of contents in force. \intex\ considers that a document consists of a {\it prelude} part that will include the preface, table of contents, and other special summaries, an {\it interlude} consisting of chapters and sections, appendices, which may appear at the end of a document or at the end of a chapter, and a {\it postlude} which would include, perhaps, an index, references, and even appendices. The {\it prelude}, appendices, and {\it postlude} are enclosed by a |\begin...\end...| pair that form a group and set up the styles appropriate for that section. The forms that introduce sections, tables of contents, or chapters all have commands of the form |\...head|, such as |\shead|, where the |head| is supposed invoke images of starting a unit. In \intex, all commands that have a |\begin...| have an accompanying |\end...| and all create a group. The |\...head| commands are key elements in controlling the setting and incrementing of the various numbers used in the document. In addition, they have a relatively complex, but accessible format part that can be modified if required. The section head commands |\chead|, |\shead|, |\sshead|, |\ssshead|, and |\dssshead| stand for chapterhead, sectionhead, subsectionhead, subsubsectionhead, and diminished subsubsectionhead. This is the only example of commands in \intex\ for which the abbreviations exist without the full forms. This is primarily for typing and visual convenience in the original file. The fonts used have the same abbreviated form. If an |\shead| is immediately followed by an |\sshead| or any other sectionhead form, there is a chance that they may be split apart if they occur at the bottom of the page. {\bf To prevent this, and to make the spacing reasonable, the command |\nosheadbreak| must be placed in between the two commands.} The general spacing parameters are given in Section \ref{sheadspac}. If the |.toc| file is open for making a table of contents list, each section head form writes information to this file. The actual form sent is determined by the definition of a |\...tocout| form. For instance the |\shtocout| is defined as |\def\shtocout{\string\shtoc}|. The |\shtoc| is an \intex\ form that produces a section head line in the table of contents. \shead{sheadcomlist}{Command List} \beginthreecolumn \hfuzz=10pt \ext|\Alphabetic| \ext|\alphabetic| \ext|\Appendix| \ext|\beginappendices| \ext|\beginprelude| \ext|\Chapter| \ext|\chapterstartform| \ext|\chead| \ext|\cheadfont| \ext|\chnum| \ext|\chtagreplaceformat| \ext|\chnumform| \ext|\chtocout| \ext|\endappendices| \ext|\endprelude| \ext|\dssshead| \ext|\dsssheadfont| \ext|\dssshtocout| \ext|\innerchead| \ext|\innerdssshead| \ext|\innershead| \ext|\innersshead| \ext|\innerssshead| \ext|\nosheadbreak| \ext|\preludehead| \ext|\prtocout| \ext|\shead| \ext|\sheadfont| \ext|\shnum| \ext|\shnumform| \ext|\shtagreplaceformat| \ext|\shtocout| \ext|\sshead| \ext|\ssheadfont| \ext|\sshnum| \ext|\sshnumform| \ext|\sshtocout| \ext|\ssshead| \ext|\sssheadfont| \ext|\ssshnum| \ext|\ssshnumform| \ext|\ssshtocout| \ext|\UpperRoman| \endthreecolumn \shead{sheadcomforms}{Command Forms --- Making Head Forms} The commands in this section are very similar in form and will be described in together. There are six predefined ||: |prelude|, |c| (chapter), |s|, |ss|, |sss|, and |dsss|. All but |prelude| and |dsss| take two arguments in their |\head| form. Number format and font commands are discussed in Section \ref{numforms}. \beginblockmode \mbr \ext\@|\chead{}{}| \nbr \ext\@|\preludehead{<title>}| \nbr \ext\@|\shead{<number or tag>}{<title>}| \nbr \ext\@|\sshead{<number or tag>}{<title>}| \nbr \ext\@|\ssshead{<number or tag>}{<title>}| \nbr \ext\@|\dssshead{<title>}| \nbr All of these commands create the various forms of section or chapter heads indicated by the command name. The |<number or tag>| field is interpreted as a tag if |autonumbering| is on or inserted as is into the appropriate place if is not. The lack of this field in |\dssshead| and |\preludehead| implies that it is impossible to tag or refer to these document parts except through their, presumably known, titles. The tag replacement format and associated |\<head type>hnumform| are discussed separately in Section \ref{numforms}. There are some restrictions in the use of the |<title>| field. This should {\bf not} include |\footnote|, |\cite|, or |\ref| commands. If it is absolutely necessary to use these, see Chapter~{\ref{footnot}} to see how to get around the |\footnote| restriction, and use |\quietref{<tag>}| for the other two. {\it Quiet} is not quite {\it silent}. \mbr \ext\@|\Appendix| \nbr This command defines the actual form that will be seen in an |\shead| used for appendices. It is defined as ``Appendix'' in |\englishversion| and ``Appendice'' in |\versionfrancaise|. \mbr \ext\@|\beginappendices \endappendices| \nbr These commands are intended to enclose the appendices that occur at the end of a chapter or book. They reset the {\it special} auto numbers, and change the format of the numbers when an |\shead| or its relatives are called. |\chead| should not be called in an appendix. Since the |\begin...\end...| pair form a group, changes that only affect the appendices are easily made. \mbr \ext\@|\beginprelude \endprelude| \nbr These commands are intended to enclose the prelude that occurs at the the start of a document. Preludes usually include such entities as prefaces, tables of contents, figures, and tables, acknowledgments, distribution lists or perhaps executive summaries. Since the |\begin...\end...| pair form a group, changes that only affect the prelude parts are easily made. \mbr \ext\@|\Chapter| \nbr This command defines the actual form used in a |\chead|. It is defined as ``Chapter'' in |\englishversion| and ``Chapitre'' in |\versionfrancaise|. \mbr \ext\@|\chapterstartform = {<special pre chapter tests>}| \nbr The token list for this command is executed inside |\chead| before the first page of the chapter is produced. For this book it was used to check whether the chapter starting page was odd. If it was not, a ``quote'' page was produced. \endblockmode \shead{numforms}{Command Forms --- Number Formats} The number formats when autonumbering is in force are defined using a few commands. First the fonts in the various head forms are called \@|\<head type>headfont|. These are defined when a document font size (see Chapter \ref{fonts}) is defined. For example |\documentfont{\tenpoint}| determined the document font family for this book. The individual fonts may be changed, although it is not recommended, by changing the |\<head type>headfont|. For example, |\let\sheadfont = \twelvedu| will change the section head font for the rest of the document, or until the end of the group if it is called within a group. A change of this sort will not modify the other fonts. The number formats are modified by changing the |\<head type>hnumform| such as |\chnumform|, |\shnumform|, |\sshnumform|, |\ssshnumform|, respectively for the chapter and the various section heads. \@|\Alphabetic{<integer>}|, \@|\alphabetic{<integer>}|, and \@|\UpperRoman{<integer>}| are used to change the format of an integer (counter) to either the equivalent uppercase letter, lowercase letter or uppercase roman numeral. The \intex\ forms for |\<head type>hnumform| are \begintt \def\<head type>hnumform{\the\<head type>hnum} \endtt for all |<head type>| except that in appendices |\shnumform| is defined to be \begintt \def\shnumform{\Alphabetic{\the\shnum}} \endtt This effectively changes the appendix numbering to be roman capitals. The command \@|\chtagreplaceformat| is the actual command that is used to place the ``Chapter \ref{shead}'' at the beginning of this chapter. The two definitions involved in this replacement are \begintt \def\chtagreplaceformat {Chapter \chtagrefformat} \def\chtagrefformat {\chnumform} \endtt The \@|\shtagreplaceformat| is defined similarly and is used in |\sheads|. A change in the form of the command written to the table of contents file may be obtained simply by redefining the appropriate |\...tocout|. \shead{sheadspac}{Command Forms --- Section Head Spacing} The spacing both before and after the various |\...head|s are determined by the following parameters. Stretch and shrink glue should be specified to give \tex\ some freedom to break pages. \bshortcomlist \ext\@|\prsheadskip [=] <glue>|& pre shead skip \cr \ext\@|\posheadskip [=] <glue>|& post shead skip \cr \ext\@|\prssheadskip [=] <glue>|& pre sshead skip \cr \ext\@|\possheadskip [=] <glue>|& post sshead skip \cr \ext\@|\prsssheadskip [=] <glue>|& pre ssshead skip \cr \ext\@|\posssheadskip [=] <glue>|& post ssshead skip \cr \ext\@|\prdsssheadskip [=] <glue>|& pre dssshead skip \cr \ext\@|\podsssheadskip [=] <glue>|& post dssshead skip \cr \eshortcomlist \shead{genform}{Major Modifications of the Section Head Formats} \intex\ has separate |\cheadformat|, \@|\preludeheadformat|, and a very general section head format. These are easily modifiable without upsetting any of the houskeeping. Any format that satisfies the input parameter constraints will work. \beginblockmode \mbr \ext\@|\cheadformat{<chapter>}{<text>}| \nbr The |<chapter>| is the chapter identifier. In this chapter it was {\bf Chapter~\ref{shead}}. The |<text>| is title of the chapter. The particular form was built using |\vcenter| and |\halign|. \mbr \ext\@|\gensheadformat{<font>}{<number>}{<text>}{<separator>}| \nbr This command uses four parameters. The first is the font, the second the number, the third is the title of the section and the fourth is the separator between the number and the text. The form that is used checks the number to see if it is empty. If it is, the |<text>| is placed flush left. The |<text>| is actually placed in a |\vbox| with |\veryraggedright| spacing so that there will be no hyphenation and long titles will automatically split. Details are in {\tt secthead.tex}. \mbr \ext\@|\preludheadformat{<title>}| \nbr This command is defined with one parameter that is assumed to be the title of the particular section. Since this one is quite simple the default definition is given as \begintt \def\preludeheadformat#1{\centerline{\sheadfont #1}\vskip 1cm} \endtt \endblockmode \ejectpage \done