summaryrefslogtreecommitdiff
path: root/Master/texmf-dist/doc/plain/impatient-cn/pages.tex
diff options
context:
space:
mode:
authorKarl Berry <karl@freefriends.org>2014-11-13 23:53:39 +0000
committerKarl Berry <karl@freefriends.org>2014-11-13 23:53:39 +0000
commite0056016e425d97e79d80fdee01acf4cd84c1d8d (patch)
treec6024370d669e546e6c66fca1784ec0a980e8694 /Master/texmf-dist/doc/plain/impatient-cn/pages.tex
parentc3397e2195329b400975b069f1f6e3b2092f84a8 (diff)
impatient-cn (13nov14)
git-svn-id: svn://tug.org/texlive/trunk@35576 c570f23f-e606-0410-a88d-b1316a301751
Diffstat (limited to 'Master/texmf-dist/doc/plain/impatient-cn/pages.tex')
-rw-r--r--Master/texmf-dist/doc/plain/impatient-cn/pages.tex1646
1 files changed, 1646 insertions, 0 deletions
diff --git a/Master/texmf-dist/doc/plain/impatient-cn/pages.tex b/Master/texmf-dist/doc/plain/impatient-cn/pages.tex
new file mode 100644
index 00000000000..108d267168d
--- /dev/null
+++ b/Master/texmf-dist/doc/plain/impatient-cn/pages.tex
@@ -0,0 +1,1646 @@
+% -*- coding: utf-8 -*-
+% This is part of the book TeX for the Impatient.
+% Copyright (C) 2003 Paul W. Abrahams, Kathryn A. Hargreaves, Karl Berry.
+% See file fdl.tex for copying conditions.
+
+\input macros
+%\chapter {Commands for \linebreak composing pages}
+\chapter {组页命令}
+
+\chapterdef{pages}
+
+这个章节介绍了与页, 页的组成部分以及输出程序相关的命令.
+本章写作惯例的说明可以在\headcit{命令描述}{cmddesc}中找到.
+
+\begindescriptions
+
+%==========================================================================
+%\section {Interline and interparagraph spaces}
+\section {行间距和段间距}
+
+\begindesc
+\cts baselineskip {\param{glue}}
+\cts lineskiplimit {\param{dimen}}
+\cts lineskip {\param{glue}}
+\explain
+%^^{line spacing}
+%\bix^^{interline glue}
+%\bix^^|\baselineskip|
+%\bix^^|\lineskip|
+%\bix^^|\lineskiplimit|
+%These three parameters jointly determine how much space \TeX\ leaves between
+%consecutive \minref{box}es of an ordinary \minref{vertical list},
+%e.g., the lines of a paragraph.
+%This space is called ``\minref{interline glue}''.
+%It is also inserted between the component boxes of a vbox constructed in
+%internal vertical mode.
+%^^{vboxes//interline glue for}
+%
+%In the usual case, when the boxes aren't abnormally high or deep, \TeX\
+%makes the distance from the baseline of one box to the baseline of the
+%next one equal to |\baselineskip|. It does this by inserting interline
+%glue equal to |\baselineskip| minus the depth of the upper box (as given
+%by ^|\prevdepth|) and the height of the lower box. But if this
+%interline glue would be less than |\lineskiplimit|, indicating that the
+%two boxes are too close together, \TeX\ inserts the |\lineskip| glue
+%instead.\footnote
+%{\TeX\ actually accounts for the beginning of a
+%vertical list by setting |\prevdepth| to $-1000$\pt\ and testing
+%|\prevdepth| before \emph{every} box. If |\prevdepth|$\>\le-1000$\pt\
+%it does not insert any interline glue.} See \knuth{pages~79--80} for a
+%precise description.
+%
+%Note that |\baselineskip| and |\lineskip| measure \emph{different
+%things}: the distance between baselines on the one hand and the distance
+%between the bottom of one box and the top of the next box on the other
+%hand. See \knuth{page~78} for further details. The first example below
+%shows the effects of |\lineskiplimit|.
+%
+%You can obtain the effect of ^{double spacing} by doubling the value
+%of |\baselineskip| as illustrated in the second example below.
+%A change to |\baselineskip| at any point before the end of a paragraph affects
+%the entire paragraph.
+^^{行间距}
+\bix^^{行间粘连}
+\bix^^|\baselineskip|
+\bix^^|\lineskip|
+\bix^^|\lineskiplimit|
+在一个普通\minref{竖直列}(例如段落各行)中,
+这三个参数共同确定了 \TeX\ 在相邻两个\minref{盒子}间插入的间隔。
+这个间隔称为“\minref{行间粘连}”。
+对于内部竖直模式中构造的竖直盒子,其中的组成盒子间同样会有此间隔。
+^^{竖直盒子//竖直盒子的行间粘连}
+
+在通常情况下,盒子的高度和深度不会太大,
+此时 \TeX\ 让相邻盒子的两基线距离等于 |\baselineskip|。
+为此可以让行间粘连等于 |\baselineskip| 减去上盒子深度(由 ^|\prevdepth| 给出)%
+和下盒子高度。
+但如果两个盒子靠得太近,即行间粘连小于 |\lineskiplimit|,
+\TeX\ 将改为插入 |\lineskip| 大小的间距。\negthinspace\footnote
+{\TeX\ 实际上在竖直列开头设定 |\prevdepth| 为 $-1000$\pt ,
+从而可以测定\emph{每个}盒子的 |\prevdepth|。
+若 |\prevdepth|$\>\le-1000$\pt ,
+它就不会插入任何行间粘连。}详情可见 \knuth{第~79--80~页}。
+
+注意 |\baselineskip| 和 |\lineskip| 测量\emph{不同的东西}:
+前者为两盒子基线之间的距离,
+而后者为上盒子底部和下盒子顶部的距离。
+详情可看 \knuth{第~78~页}。
+下面第一个例子展示了|\lineskiplimit| 的作用。
+
+如下面第二个例子所示,将 |\baselineskip| 加倍,
+就能得到^{双倍行距}的效果。
+在段落结束前任何位置改变 |\baselineskip|,都会影响整个段落。
+\example
+\baselineskip = 11pt \lineskiplimit = 1pt
+\lineskip = 2pt plus .5pt
+Sometimes you'll need to typeset a paragraph that has
+tall material, such as a mathematical formula, embedded
+within it. An example of such a formula is $n \choose k$.
+Note the extra space above and below this line as
+compared with the other lines.
+(If the formula didn't project below the line,
+we'd only get extra space above the line.)
+|
+\produces
+\baselineskip = 11pt \lineskiplimit = 1pt
+\lineskip = 2pt plus .5pt
+Sometimes you'll need to typeset a paragraph that has
+tall material, such as a mathematical formula, embedded
+within it. An example of such a formula is $n \choose k$.
+Note the extra space above and below this line as
+compared with the other lines.
+(If the formula didn't project below the line,
+we'd only get extra space above the line.)
+\endexample
+
+\example
+\baselineskip = 2\baselineskip % Start double spacing.
+|
+\endexample
+
+%\eix^^{interline glue}
+%\eix^^|\baselineskip|
+%\eix^^|\lineskip|
+%\eix^^|\lineskiplimit|
+%\enddesc
+\eix^^{行间粘连}
+\eix^^|\baselineskip|
+\eix^^|\lineskip|
+\eix^^|\lineskiplimit|
+\enddesc
+
+\begindesc
+\cts prevdepth {\param{dimen}}
+\explain
+%When \TeX\ adds a box to a vertical list, it sets |\prevdepth| to the
+%depth of that box. \TeX\ sets |\prevdepth| to $-1000$\pt\ at the start
+%of a vertical list, indicating that the usual interline glue should be
+%suppressed.
+当 \TeX\ 将盒子添加到竖直列时,它设定 |\prevdepth| 为该盒子的深度。
+在竖直列的开始, \TeX\ 设定 |\prevdepth| 为 $-1000$\pt\ ,这表示不添加行间粘连。
+\enddesc
+
+\begindesc
+\cts normalbaselineskip {\param{glue}}
+\cts normallineskiplimit {\param{dimen}}
+\cts normallineskip {\param{glue}}
+\cts normalbaselines {}
+\explain
+%The three parameters contain values for |\base!-line!-skip|,
+%|\line!-skip|, and |\line!-skip!-limit| respectively.
+%^^|\baselineskip| ^^|\lineskip| ^^|\lineskiplimit|
+%The |\normalbaselines| command sets |\base!-line!-skip|,
+%|\line!-skip|, and |\line!-skip!-limit| to the values contained in the
+%three parameters.
+前三个参数分别包含 |\base!-line!-skip|,|\line!-skip| 和 |\line!-skip!-limit| 的值。
+^^|\baselineskip| ^^|\lineskip| ^^|\lineskiplimit|
+而 |\normalbaselines| 命令将 |\base!-line!-skip|,|\line!-skip| 和 |\line!-skip!-limit|
+分别设定为这三个参数的值。
+\enddesc
+
+\begindesc
+\cts offinterlineskip {}
+\explain
+%This command tells \TeX\ to stop inserting interline glue from
+%now on. Unless you want it to be in effect for the rest of the document
+%(which you probably don't), you should enclose it in a group
+%together with the text you want it to affect.
+%Its main purpose is to let you do interline spacing yourself,
+%e.g., using ^{struts},
+%without interference from \TeX's normal interline glue.
+%|\offinterlineskip| is often useful when
+%you're constructing a horizontal \minref{alignment}.
+%^^{alignments//using \b\tt\\offinterlineskip\e\ in}
+此命令让 \TeX\ 从此之后停止插入行间粘连。除非你希望对文档的剩余部分都生效(你多半不希望),
+你应该将此命令和你希望生效的文本放在一个编组中。
+它的主要用处在于可以让你自己处理行间空隙,比如用^{支架}(struts),
+而不影响 \TeX\ 的正常行间粘连。在构造水平\minref{阵列}时经常会用到|\offinterlineskip|。
+^^{阵列//在其中使用 \b\tt\\offinterlineskip\e}
+\example
+\def\entry#1:#2 {\strut\quad#1\quad&\quad#2\quad\cr}
+\offinterlineskip \tabskip = 0pt \halign{%
+\vrule\quad\hfil#\hfil\quad\vrule&
+ \quad\hfil#\hfil\quad\vrule\cr
+\noalign{\hrule}
+\vphantom{\vrule height 2pt}&\cr \noalign{\hrule}
+\entry \it Opera:\it Composer
+\vphantom{\vrule height 2pt}&\cr \noalign{\hrule}
+\vphantom{\vrule height 2pt}&\cr
+\entry Fidelio:Beethoven
+\entry Peter Grimes:Britten
+\entry Don Giovanni:Mozart
+\vphantom{\vrule height 2pt}&\cr \noalign{\hrule}}
+|
+\produces
+\medskip
+\def\entry#1:#2 {\strut\quad#1\quad&\quad#2\quad\cr}
+\offinterlineskip \tabskip = 0pt \halign{%
+\vrule\quad\hfil#\hfil\quad\vrule&
+ \quad\hfil#\hfil\quad\vrule\cr
+\noalign{\hrule}
+\vphantom{\vrule height 2pt}&\cr \noalign{\hrule}
+\entry \it Opera:\it Composer
+\vphantom{\vrule height 2pt}&\cr \noalign{\hrule}
+\vphantom{\vrule height 2pt}&\cr
+\entry Fidelio:Beethoven
+\entry Peter Grimes:Britten
+\entry Don Giovanni:Mozart
+\vphantom{\vrule height 2pt}&\cr \noalign{\hrule}}
+\endexample
+\enddesc
+
+\begindesc
+\cts nointerlineskip {}
+\explain
+%This command tells \TeX\ not to insert interline glue in front of the
+%next line.
+%It has no effect on subsequent lines.
+此命令让 \TeX\ 停止在下一行插入行间粘连。它不影响后续其他行。
+\enddesc
+
+\begindesc
+\cts openup {\<dimen>}
+\explain
+%This command increases ^|\baselineskip| by \<dimen>.
+%An |\openup| command before the end of a paragraph affects
+%the entire paragraph, so you shouldn't use |\openup| to
+%change |\baseline!-skip| within a paragraph. |\openup| is
+%most useful for typesetting tables and math displays---a
+%little extra space between rows often makes them more readable.
+%^^{alignments//space between rows of}
+此命令让 ^|\baselineskip| 增加 \<dimen>。
+在段尾之前的 |\openup| 命令将影响整个段落,
+因此想在段落中间改变 |\baseline!-skip| 时不要用 |\openup| 命令。
+在排版表格和陈列公式时 |\openup| 非常有用——多点间隔将会增加它们的可读性。
+^^{阵列//各行之间的间隔}
+\example
+Alice picked up the White King very gently, and lifted him
+across more slowly than she had lifted the Queen; but before
+she put him on the table, she thought she might well dust
+him a little, he was so covered with ashes.
+\openup .5\baselineskip % 1.5 linespacing.
+|
+\produces
+Alice picked up the White King very gently, and lifted him
+across more slowly than she had lifted the Queen; but before
+she put him on the table, she thought she might well dust
+him a little, he was so covered with ashes.
+\openup .5\baselineskip %1.5 linespacing
+\endexample\enddesc
+
+%==========================================================================
+\section{分页} %\section {Page breaks}
+
+%==========================================================================
+%\subsection {Encouraging or discouraging page breaks}
+\subsection{鼓励或阻碍分页}
+
+%\begindesc
+%\bix^^{page breaks}
+%\bix^^{page breaks//encouraging or discouraging}
+%\ctspecial break {} \xrdef{vbreak}
+%\explain
+\begindesc
+\bix^^{分页}
+\bix^^{分页//鼓励或阻碍分页}
+\ctspecial break {} \xrdef{vbreak}
+\explain
+%
+\margin{Four commands identical to ones for line breaks (\xref{hbreak})
+have been added to correct an omission. The descriptions are exactly parallel.}
+%
+%This command forces a page break.
+%Unless you do something to fill out the page, you're likely to
+%get an underfull vbox.
+%|\break| can also be used in horizontal mode.
+此命令强制在此处分页。除非用某种方式填满该页,你将得到一个松散的 vbox。
+|\break| 也能用在水平模式中。
+\enddesc
+
+\begindesc
+\ctspecial nobreak {} \xrdef{vnobreak}
+\explain
+%This command prevents a page break where it
+%otherwise might occur.
+%|\nobreak| can also be used in horizontal mode.
+此命令阻止在此处分页。
+|\nobreak| 也能用在水平模式中。
+\enddesc
+
+\begindesc
+\ctspecial allowbreak {} \xrdef{vallowbreak}
+\explain
+%This command tells \TeX\ to
+%allow a page break where one could not ordinarily occur.
+%|\allowbreak| can also be used in horizontal mode.
+在通常不分页的地方允许 \TeX\ 分页。
+|\allowbreak| 也能用在水平模式中。
+\enddesc
+
+\begindesc
+\ctspecial penalty {\<number>} \xrdef{vpenalty}
+\explain
+%This command produces a \minref{penalty} item.
+%The penalty item makes \TeX\ more or less willing to break a page
+%at the point where that item occurs.
+%A negative penalty, i.e., a bonus, encourages a page break;
+%a positive penalty discourages a page break.
+%A penalty of $10000$ or more prevents a break altogether,
+%while a penalty of $-10000$ or less forces a break.
+%|\penalty| can also be used in horizontal mode.
+此命令生成一个惩罚(\minref{penalty})项。
+惩罚项使得 \TeX\ 或多或少愿意在此处分页。
+负惩罚值,实际上是奖励值,鼓励分页;正惩罚值阻碍分页。
+大于或等于 $10000$ 的惩罚值彻底阻止分页,
+而小于或等于 $-10000$ 的惩罚值强制分页。
+此命令也能用于水平模式。
+\example
+\def\break{\penalty-10000 } % as in plain TeX
+\def\nobreak{\penalty10000 } % as in plain TeX
+\def\allowbreak{\penalty0 } % as in plain TeX
+|
+\endexample
+\enddesc
+
+\begindesc
+\cts goodbreak {}
+\explain
+%This command ends a paragraph and also indicates to \TeX\ that
+%this is a good place to break the page.
+此命令结束当前段落,并告诉 \TeX\ 这里是一个合适的分页位置。
+\enddesc
+
+\begindesc
+\cts smallbreak {}
+\cts medbreak {}
+\cts bigbreak {}
+\explain
+%These commands indicate increasingly desirable places for \TeX\ to
+%break a page. They also cause \TeX\ to
+%insert a ^|\smallskip|, ^|\medskip|, or
+%^|\bigskip| (\xref \smallskip) if the page break doesn't actually
+%happen. \TeX\ suppresses this skip if it occurs just after an
+%equal or larger skip.
+这些命令指明了越来越合适的分页位置。如果实际上没在此处分页,\TeX\ 将分别
+插入大小为 ^|\smallskip|,^|\medskip| 或 ^|\bigskip| 的间距(\xref \smallskip )。
+但如果此位置之前已经有大于或等于此值的间距,\TeX\ 就不会再插入间距。
+\enddesc
+
+\begindesc
+\easy\cts eject {}
+\cts supereject {}
+\explain
+%These commands force a page break at the current position
+%and end the current paragraph.
+%If you don't precede them with |\vfil| (\xref \vfil),
+%^^|\vfil//needed with {\tt\\eject}|
+%\TeX\ will try to stretch out the page contents
+%(and will probably complain about an underfull vbox).
+%The |\supereject| command, in addition,
+%instructs the \plainTeX\ output routine to
+%force out any leftover insertions,
+%^^{insertions//forced out by \b\tt\\supereject\e}
+%such as long footnotes,
+%so that they are produced before any more input
+%is processed. Thus |\supereject| is a good command to use at the end of each
+%chapter or other major unit of your document.
+这两个命令将结束当前段落并强制在当前位置分页。如果你不在前面加上
+|\vfil| (\xref \vfil),^^|\vfil//在 {\tt\\eject} 时需要|
+\TeX\ 将试着将伸展页面内容(很可能会警告有松散的竖直盒子)。
+|\supereject| 命令还让 \plainTeX\ 输出例行程序处理剩下的插入项,
+^^{插入项//用 \b\tt\\supereject\e 强制排版}例如长脚注,
+在处理其他输入之前生成它们。因而,
+|\supereject| 更适合在文档各章或主要单元结束时使用。
+\enddesc
+
+\begindesc
+\cts filbreak {}
+\explain
+%This command provides a kind of conditional page break.
+%It tells \TeX\ to
+%break the page---but not if the text up to a later |\filbreak| also
+%fits on the same page.
+%By enclosing a paragraph in a pair of |\filbreak|s,
+%you can ensure that \TeX\ will keep a paragraph on a single page if it can.
+%You should not use |\filbreak| within a paragraph, since it
+%forces \TeX\ into vertical mode and thus ends the paragraph.
+%See \xrefpg{filbreak} for more advice on this subject.
+此命令规定了有条件的分页。它告诉 \TeX\ ,如果后面的 |\filbreak| 不能放在同一页,就在此处分页。
+用一对 |\filbreak| 将一个段落围起来,就可以确保 \TeX\ 尽量将该段落放在同一页。
+不要在段落中间使用 |\filbreak|,因为这将让 \TeX\ 进入竖直模式,从而结束该段落。
+在 \xrefpg{filbreak} 中有此主题的更多建议。
+\enddesc
+
+\begindesc
+\cts raggedbottom {}
+\cts normalbottom {}
+\explain
+%Normally \TeX\ tries hard to ensure that all pages have the same depth,
+%i.e., that their bottom margins are equal.
+%The |\raggedbottom| command tells \TeX\ to
+%allow some variability among the bottom margins on different pages.
+%It's often appropriate to use |\raggedbottom| when you have material that
+%contains large blocks of material that should not be split across pages.
+%The |\normalbottom| command cancels the effect of |\raggedbottom|.
+%\eix^^{page breaks//encouraging or discouraging}
+通常 \TeX\ 会尽全力让每页都一样高,即让它们的下边距相等。
+|\raggedbottom| 命令允许 \TeX\ 给不同页面的下边距一些差别。
+如果文档中有些不能跨页的大型内容,用 |\raggedbottom| 就比较合适。
+用 |\normalbottom| 命令可以取消 |\raggedbottom| 的效果.
+\eix^^{分页//鼓励或阻碍分页}
+\enddesc
+
+%==========================================================================
+%\subsection {Page breaking parameters}
+\subsection{分页参数}
+
+%\bix^^{page breaks//parameters for}
+%\begindesc
+%\cts interlinepenalty {\param{number}}
+%\explain
+%This parameter specifies the \minref{penalty} for
+%breaking a page between the lines of a paragraph.
+%By setting it to $10000$ you can force all page breaks to occur
+%between paragraphs, provided that the pages have enough stretch so
+%that \TeX\ can still compose them decently.
+%\PlainTeX\ leaves |\inter!-linepenalty| at~$0$.
+\bix^^{分页//分页参数}
+\begindesc
+\cts interlinepenalty {\param{number}}
+\explain
+此参数设定在段落内部各行间分页时的\minref{惩罚}值。
+将它设为 $10000$ 将强制在段落之间分页,
+只要页面中有足够的伸展值让 \TeX\ 排版。
+\PlainTeX\ 设定 |\inter!-linepenalty| 为 ~$0$。
+\enddesc
+
+\begindesc
+\cts clubpenalty {\param{number}}
+\explain
+%^^{club line}
+%This parameter specifies the \minref{penalty} for
+%breaking a page just after the first line of a paragraph.
+%A line by itself at the bottom of a page is called a ``club line''.
+%\PlainTeX\ sets |\clubpenalty| to $150$.
+^^{孤行}
+此参数设定在段落首行之后分页的\minref{惩罚}值。
+页面底部的单独一行称为``孤行''。
+\PlainTeX\ 设定 |\clubpenalty| 为 $150$。
+\enddesc
+
+\begindesc
+\cts widowpenalty {\param{number}}
+\explain
+%^^{widow line}
+%This parameter specifies the \minref{penalty} for
+%breaking a page just before the last line of a paragraph.
+%A line by itself at the top of a page is called a ``widow line''.
+%\PlainTeX\ sets |\widowpenalty| to $150$.
+^^{寡行}
+此参数设定在段落尾行之前分页的\minref{惩罚}值。
+页面顶部的单独一行称为``寡行''。
+\PlainTeX\ 设定 |\widowpenalty| 为 $150$。
+\enddesc
+
+\begindesc
+\cts displaywidowpenalty {\param{number}}
+\explain
+%^^{widow line}^^{math display}
+%This parameter specifies the \minref{penalty} for
+%breaking a page just before the last line of a partial paragraph
+%that immediately precedes a math display.
+%\PlainTeX\ sets |\displaywidowpenalty| to $50$.
+^^{寡行}^^{陈列公式}
+此参数设定在陈列公式上一行同时也是段落尾行之前分页的\minref{惩罚}值。
+\PlainTeX\ 设定 |\displaywidowpenalty| 为 $50$.
+\enddesc
+
+\begindesc
+\cts predisplaypenalty {\param{number}}
+\explain
+%^^{math display}
+%This parameter specifies the \minref{penalty} for
+%breaking a page just before a math display.
+%\PlainTeX\ sets |\predisplaypenalty| to $10000$.
+^^{陈列公式}
+此参数设定在陈列公式之前分页的\minref{惩罚}值。
+\PlainTeX\ 设定\break |\pre!-display!-penalty| 为 $10000$。
+\enddesc
+
+\begindesc
+\cts postdisplaypenalty {\param{number}}
+\explain
+%^^{math display}
+%This parameter specifies the \minref{penalty} for
+%breaking a page just after a math display.
+%\PlainTeX\ leaves |\postdisplaypenalty| at $0$.
+^^{陈列公式}
+此参数设定在陈列公式之后分页的\minref{惩罚}值。
+\PlainTeX\ 设定\break |\postdisplaypenalty| 为 $0$。
+\enddesc
+
+\begindesc
+\cts brokenpenalty {\param{number}}
+\explain
+%This parameter specifies the \minref{penalty} for
+%breaking a page just after a line that ends in
+%a discretionary item (usually a hyphen).
+%^^{hyphenation}
+%|\brokenpenalty| applies to page breaking, while
+%^|\hyphenpenalty| \ctsref{\hyphenpenalty} applies to line breaking.
+%\PlainTeX\ sets |\brokenpenalty| to $100$.
+此参数设定在以自定连字项(通常是一个连字符)结尾的一行之后分页的\minref{惩罚}值。
+^^{连字}
+|\brokenpenalty| 用于分页, 而 ^|\hyphenpenalty| \ctsref{\hyphenpenalty} 用于断行。
+\PlainTeX\ 设定 |\brokenpenalty| 为 $100$.
+\enddesc
+
+\begindesc
+\cts insertpenalties {\param{number}}
+\explain
+%\bix^^{insertions//penalties for}
+%\bix^^{floating material}
+%This parameter contains the sum of certain penalties \minrefs{penalty}
+%that \TeX\ accumulates as it is placing insertions onto the
+%current page.
+%These penalties are incurred when \TeX\ is processing an |\insert|
+%command
+%and discovers that a previous insertion of the same kind on this page has
+%been split, leaving part of it for subsequent pages.
+%See \knuth{pages~123--125} for the details of this
+%calculation.
+%
+%\margin{Material moved from a footnote to the main text.}
+%|\insertpenalties| has an entirely different meaning during an
+%^^{output routine//meaning of \b\tt\\insertpenalties\e\ in}
+%output routine---it's the number of insertions that have been seen
+%but that don't fit on the current page (see \knuth{page~125}).
+\bix^^{插入项//插入项的惩罚}
+\bix^^{浮动体}
+此参数包含 \TeX\ 放置插入项到当前页面时所累积的某些\minref{惩罚}值之和。
+在 \TeX\ 处理 |\insert| 命令时,
+如果发现前面有同类型插入项被分开,留下一部分到之后的页面,
+就会算上这些惩罚值。
+详细的计算过程可以见 \knuth{第~123--125~页}。
+
+\margin{Material moved from a footnote to the main text.}
+在输出例行程序中,
+^^{输出例行程序//\b\tt\\insertpenalties\e\ 的意义}
+|\insertpenalties| 有完全不同的意义——
+它表示已经见到但未能放入当前页的插入项的总数(见 \knuth{第~125~页})。
+\enddesc
+
+\begindesc
+\cts floatingpenalty {\param{number}}
+\explain
+%This parameter specifies the \minref{penalty} that
+%\TeX\ adds to |\insertpenalties|
+%^^|\insertpenalties|
+%when the page builder is adding an insertion to the current page
+%and discovers that a previous insertion of the same kind on this page has
+%been split, leaving part of it for subsequent pages.
+%\PlainTeX\ leaves |\floatingpenalty| at~$0$.
+%\eix^^{insertions//penalties for}
+%\eix^^{floating material}
+在 \TeX\ 处理插入项时,
+如果发现前面有同类型插入项被分开,留下一部分到之后的页面,
+就会添加 |\floatingpenalty| \minref{惩罚}值到|\insertpenalties|
+^^|\insertpenalties|。
+\PlainTeX\ 设定 |\floatingpenalty| 为 $0$。
+\eix^^{插入项//插入项的惩罚}
+\eix^^{浮动体}
+\enddesc
+
+\begindesc
+\cts pagegoal {\param{dimen}}
+\explain
+%This parameter specifies the
+%desired height for the current page.
+%\TeX\ sets
+%|\pagegoal| to the current value of |\vsize|
+%when it first puts a box or an insertion on the current page.
+%You can shorten a page while \TeX\ is working on it by
+%changing the value of |\pagegoal|---even if the new value is
+%less than the height of the material already on that page.
+%\TeX\ will just put the extra material on the next page.
+%But remember---|\pagegoal| is reset to |\vsize| again when \TeX\
+%starts the next page.
+此参数设定当前页面所需的高度。
+当放入第一个盒子或者插入项到当前页面时,
+\TeX\ 设定 |\pagegoal| 等于 |\vsize| 的当前值。
+改变 |\pagegoal| 的值可以让 \TeX\ 排版时缩短该页面的高度。
+即使新的值比页面已有内容的高度还小也可以,
+此时 \TeX\ 将把多余的内容放在下一页。
+但记住——在下一页 \TeX\ 还是会重置 |\pagegoal| 为 |\vsize|。
+\enddesc
+
+\begindesc
+\cts pagetotal {\param{dimen}}
+\explain
+%This parameter specifies the
+%accumulated natural height of the current page.
+%\TeX\ updates |\pagetotal| as it adds
+%items to the main \minref{vertical list}.
+此参数表示当前页面累积的自然高度。
+\TeX\ 添加内容到\minref{竖直列}时会更新 |\pagetotal| 的值。
+\enddesc
+
+\begindesc
+\cts pagedepth {\param{dimen}}
+\explain
+%This parameter specifies the depth of the current page.
+%\TeX\ updates |\pagedepth| as it adds
+%items to the main \minref{vertical list}.
+此参数表示当前页面的深度。
+\TeX\ 添加内容到\minref{竖直列}时会更新 |\pagedepth| 的值。
+\enddesc
+
+\begindesc
+\cts pageshrink {\param{dimen}}
+\explain
+%This parameter specifies the amount of \minref{shrink}
+%in the accumulated \minref{glue} on the current page.
+%\TeX\ updates |\pageshrink| as it adds
+%items to the main \minref{vertical list}.
+此参数表示当前页面累积的粘连的可收缩量。
+\TeX\ 添加内容到\minref{竖直列}时会更新 |\pageshrink| 的值。
+\enddesc
+
+\begindesc
+\cts pagestretch {\param{dimen}}
+\cts pagefilstretch {\param{dimen}}
+\cts pagefillstretch {\param{dimen}}
+\cts pagefilllstretch {\param{dimen}}
+\explain
+%These four parameters together specify the amount of \minref{stretch}
+%in the \minref{glue} on the current page. The amount of stretch has
+%the form
+%{\def\f#1{\hbox{\tt fi#1}}%
+%$n_0 + n_1\f{l} + n_2\f{ll} + n_3\f{lll}$}, with the four parameters
+%giving the values of the four $n_i$.
+%\TeX\ updates these parameters as it adds
+%items to the main \minref{vertical list}.
+%
+%\eix^^{page breaks//parameters for}
+%\eix^^{page breaks}
+这四个参数合起来表示当前页面累积的粘连的可伸长量。可伸长量总共等于
+{\def\f#1{\hbox{\tt fi#1}}
+$n_0 + n_1\f{l} + n_2\f{ll} + n_3\f{lll}$},
+其中四个参数给出四个$n_i$的值。
+\TeX\ 添加内容到\minref{竖直列}时会更新这些参数的值。
+\eix^^{分页//分页参数}
+\eix^^{分页}
+\enddesc
+
+%==========================================================================
+%\section{Page layout}
+\section{页面布局}
+
+%\subsection {Page description parameters}
+\subsection {页面描述参数}
+
+\begindesc
+\bix^^{页面尺寸}
+\margin{This command was also described in the `Paragraphs' section.
+The combined description now appears there.}
+\aux\cts hsize {\param{dimen}}
+\explain
+%This parameter specifies the current line length.
+%See \xrefpg{\hsize} for a more complete explanation.
+此参数指定当前行的长度。\PlainTeX\ 设定 |\hsize| 为 |6.5in|。
+在\xrefpg{\hsize} 有完整的解释。
+\enddesc
+
+\begindesc
+\cts vsize {\param{dimen}}
+\explain
+%This parameter specifies the current vertical extent of a page.
+%\TeX\ examines it only when it is starting a page. Thus if you change
+%|\vsize| in the
+%middle of a page, your change won't affect anything until the following page.
+%If you want to change the vertical extent of a page when
+%you're in the middle of it, you should assign the new
+%height to ^|\pagegoal| (\xref \pagegoal) instead. (If you
+%want the change to affect the following pages too, you should
+%change \emph{both} |\vsize| and |\pagegoal|.)
+%\PlainTeX\ sets |\vsize| to |8.9in|.
+%\eix^^{page dimensions}
+此参数指定页面的竖直长度。
+\TeX\ 仅在页面开始时检查此值。
+因此,在页面中间改变 |\vsize| 到下一页才会生效。
+若要在页面中间改变其竖直长度,应该修改 ^|\pagegoal|(\xref \pagegoal )的值。%
+(若要改变当前页面开始的所有页面,你需要\emph{同时}修改 |\vsize| 和 |\pagegoal|。)
+\PlainTeX\ 设定 |\vsize| 为 |8.9in|。
+\eix^^{页面尺寸}
+\enddesc
+
+%\begindesc
+%\cts hoffset {\param{dimen}}
+%\cts voffset {\param{dimen}}
+%\margin{These commands were moved up from later in the subsection.}
+%^^{page origin}
+%\idxsee{origin}{page origin}
+%\explain
+%\TeX\ normally takes the ``origin'' of a page, that is, the point where
+%it starts printing, as being one inch down from the top of the page and one
+%inch to the right of the left end of the page.\footnote{
+%\TeX\ itself is indifferent to where the origin of the page is,
+%but this information has to be built into the device drivers
+%^^{device drivers//page origin known to}
+%that convert \dvifile s into printable form so that different devices
+%will yield the same results.}
+%The values of |\hoffset| and
+%|\voffset| give the horizontal and vertical offset of the actual origin
+%from this point. Thus if |\hoffset| and |\voffset| are both
+%zero, \TeX\ uses its normal origin.
+\begindesc
+\cts hoffset {\param{dimen}}
+\cts voffset {\param{dimen}}
+\margin{These commands were moved up from later in the subsection.}
+^^{页面起点}
+\idxsee{origin}{page origin}
+\explain
+\TeX\ 通常设定页面的“起点”——即它开始打印的地方——在离上页边和左页边均为一英寸的地方。\footnote{
+\TeX\ 本身并不关心页面起点的位置,
+但设备驱动程序将 \dvifile 转换为可打印形式时要用到,
+此位置信息使得在不同的设备中能得到相同的结果。
+^^{设备驱动//它所知的页面起点}}
+|\hoffset| 和 |\voffset| 的值分别给出实际起点相对该点的水平和竖直偏移量。
+因此,若 |\hoffset| 和 |\voffset| 均为零,\TeX\ 就使用正常起点。
+\example
+\hoffset = -.3in
+ % Start printing .7 inches from left edge of paper.
+\voffset = 1in
+ % Start printing 2 inches from top edge of paper.
+|
+\endexample
+\enddesc
+
+\begindesc
+\cts topskip {\param{glue}}
+\explain
+%\TeX\ inserts glue at the top of each
+%page in order to ensure that the baseline of the first box on the page
+%always is the same distance $d$ from the top of the page.
+%|\topskip| determines the amount of that glue,
+%called the ``|\topskip| glue'', by specifying
+%what $d$ should be (provided that the first box
+%on the page isn't too tall).
+%$d$ is given by the natural size of the |\topskip| glue.
+%If the height of the first box on the page exceeds $d$,
+%so that the glue would be negative, \TeX\ simply inserts no
+%|\topskip| glue at all on that page.
+为确保页面第一个盒子的基线到上页边的距离总是 $d$,
+\TeX\ 在每个页面顶部都插入粘连。
+|\topskip| 给出了 $d$ 的值,以此确定该粘连大小
+(只要页面第一个盒子不会太高)。
+$d$ 等于 |\topskip| 粘连的自然大小。
+如果页面第一个盒子的高度超过 $d$,
+计算出的粘连将为负值,此时在该页顶部 \TeX\ 不插入|\topskip|粘连。
+
+%To understand better the effect of these rules, assume that |\topskip|
+%has no stretch or shrink and that the first item on the page is indeed a box.
+%Then if the height of that box is no greater than |\topskip|,
+%its baseline will be |\topskip|
+%from the top of the page independently of its height. On the other hand,
+%if the height of the box is $e$ greater than |\topskip|, its baseline will be
+%|\topskip|\tplus$e$ from the top of the page.
+%See \knuth{pages~113--114} for the remaining details of how
+%|\topskip| works.
+%\PlainTeX\ sets |\topskip| to |10pt|.
+为更好地理解这些规则,我们假设 |\topskip| 无伸长量也无收缩量,且页面第一项就是个盒子。
+如果该盒子的高度不大于 |\topskip|,不管高度为多少,
+它的基线和上页边的距离就始终等于 |\topskip|。
+反过来,如果该盒子的高度比 |\topskip| 大 $e$,
+它的基线和上页边的距离就是 |\topskip|\tplus$e$。
+在 \knuth{第~113--114~页} 中详细解释了 |\topskip| 的作用。
+\PlainTeX\ 设定 |\topskip| 为 |10pt|。
+\enddesc
+
+\begindesc
+\cts parskip {\param{glue}}
+\explain
+%This parameter specifies the ``^{paragraph skip}'', i.e., the
+%vertical glue that \TeX\ inserts at the start of a paragraph.
+%^^{paragraphs//glue between}
+%See |\par| (\xref{\@par}) for more information about what happens
+%when \TeX\ starts a paragraph.
+%\PlainTeX\ sets |\parskip| to |0pt plus 0.1pt|.
+此参数设定“^{段落间距}”,即 \TeX\ 在段落开头插入的竖直粘连。
+^^{段落//段落间的粘连}
+在 |\par| (\xref{\@par}) 那里介绍了 \TeX\ 开始新段落时所作的事情。
+\PlainTeX\ 设定 |\parskip| 为 |0pt plus 0.1pt|。
+\enddesc
+
+\begindesc
+\cts maxdepth {\param{dimen}}
+\explain
+%This parameter specifies the maximum depth of the bottom \minref{box} on
+%a page. It is related to |\boxmaxdepth| (\xref \boxmaxdepth). If the
+%depth of the bottom box on a page exceeds |\maxdepth|, \TeX\ moves the
+%box's reference point down so that it's
+%|\maxdepth| from the bottom of that box.
+%Without this adjustment, the bottom box on
+%a page could extend well into the bottom margin or even off
+%the page entirely. \PlainTeX\ sets |\maxdepth| to |4pt|.
+此参数设定页面底部\minref{盒子}的最大深度。
+它和 |\boxmaxdepth| 参数(\xref \boxmaxdepth )也有关系.
+如果底部盒子的深度超过 |\maxdepth|,
+\TeX\ 下移该盒子的基准点,让深度就等于 |\maxdepth|。
+若不作此调整,页面底部盒子可能大大超出下边距,甚至超出页面,
+PlainTeX\ 设定 |\maxdepth| 为 |4pt|。
+\enddesc
+
+%==========================================================================
+%\subsection{Page numbers}
+\subsection{页码}
+
+%\begindesc
+%\bix^^{page numbering}
+%\cts pageno {\param{number}}
+%\explain
+%This parameter contains the current page number as an integer. The page
+%number is normally negative for front-matter pages that are numbered
+%with small roman numerals instead of arabic numerals. If you change the
+%page number within a page,
+%the changed number will be used in any headers or footers that
+%appear on that page.
+%The actual
+%printing of page numbers is handled by \TeX's \minref{output routine},
+%which you can modify.
+\begindesc
+\bix^^{页码}
+\cts pageno {\param{number}}
+\explain
+此参数以整数值记录当前页码。
+在前页(front matter)中页码通常是负数,我们用小写罗马数字而不用阿拉伯数字编号。
+在页面中间对页码的改动,会在该页的页眉和页脚中用到。
+页码事实上由 \TeX\ 的\minref{输出例行程序}打印,你可以修改它们。
+
+%\PlainTeX\ keeps the page number in the \minref{register} ^|\count0|.
+%(|\pageno| is, in fact, a synonym for |\count0|.)
+%Whenever it ships out a page to the \dvifile,
+%^^|\shipout//{\tt\\count} registers displayed at|
+%\TeX\ displays the current value of |\count0| on your
+%terminal so that you can tell which page it is working on.
+%It's possible to use registers |\count1|--|\count9| for nested
+%levels of page numbers (you must program this yourself).
+%If any of these registers are nonzero, \TeX\ displays them on your
+%terminal also.\footnote{
+%More precisely, it displays all registers in sequence from
+%|\count0| to |\count9|, but omits trailing zero registers.
+%For instance, if the values of |\count0|--|\count3|
+%are $(17, 0 , 0, 7)$ and the others are $0$,
+%\TeX\ displays the page number as {\tt [17.0.0.7]}.}
+\PlainTeX\ 将页码记录在\minref{寄存器} ^|\count0| 中。%
+(|\pageno| 实际上就是|\count0|的别名。)
+当它输出一个页面到 \dvifile 时,
+^^|\shipout//此时显示 {\tt\\count} 寄存器的值|
+\TeX\ 在终端中显示 |\count0| 的值,让你知道它在排版哪一页。
+也可以把寄存器 |\count1|--|\count9| 用于嵌套的多级页码
+(但你必须自己编程)。
+如果这些寄存器的值非零,\TeX\ 在终端中也显示它们的值。\footnote{
+更准确来说,它从 |\count0| 到 |\count9| 依次显示各寄存器的值,但忽略末尾的零值。
+比如,若 |\count0| 到 |\count3| 为 $(17, 0 , 0, 7)$ 而其他值都为 $0$,
+则 \TeX\ 显示页码为 {\tt [17.0.0.7]}。}
+\example
+This explanation appears on page \number\pageno\
+of our book.
+|
+\produces
+This explanation appears on page \number\pageno\
+of our book.
+
+\nextexample
+\pageno = 30 % Number the next page as 30.
+Don't look for this explanation on page \number\pageno.
+|
+\produces
+Don't look for this explanation on page 30.
+\endexample
+\enddesc
+
+\begindesc
+\cts advancepageno {}
+\explain
+%This command adds $1$ to the page number
+%$n$ in |\pageno| if $n\ge0$
+%and subtracts $1$ from it if $n<0$.
+如果页码 $n\ge0$,此命令给 $n$ 加上 $1$;
+如果 $n<0$ 则给 $n$ 减去 $1$。
+\enddesc
+
+\begindesc
+\easy\cts nopagenumbers {}
+\explain
+%By default, \plainTeX\ produces a footer containing a centered page number.
+%This command tells \TeX\ to produce a blank footer instead.
+默认情况下,\plainTeX\ 会在页面的页脚生成居中的页码。
+此命令让 \TeX\ 生成空的页脚.
+\enddesc
+
+\begindesc
+\cts folio {}
+\explain
+%This command produces the current page number, whose value is the number
+%$n$ contained in ^|\pageno|.
+%If $n\ge0$,
+%\TeX\ produces $n$ as a decimal number,
+%while if $n<0$,
+%\TeX\ produces $-n$ in lowercase roman numerals.
+此命令生成当前页码,它的值等于记录在 ^|\pageno| 中的 $n$。
+若 $n\ge0$,\TeX\ 用十进制数形式生成 $n$;
+若 $n<0$,\TeX\ 用小写罗马数字形式生成 $-n$。
+\example
+This explanation appears on page \folio\ of the book.
+|
+\produces
+This explanation appears on page \folio\ of the book.
+\endexample
+
+%\eix^^{page numbering}
+%\enddesc
+\eix^^{页码}
+\enddesc
+
+%==========================================================================
+%\subsection{Header and footer lines}
+\subsection{页眉和页脚}
+
+\begindesc\secondprinting{\vglue-.75\baselineskip\vskip0pt}
+\cts headline {\param{token list}}
+\cts footline {\param{token list}}
+\explain
+%These parameters
+%contain, respectively, the current headline (header) and the current
+%footline (footer).
+%The \plainTeX\ output routine
+%places the headline at the top of each page and the footline
+%at the bottom of each page.
+%The default headline is empty and the default footline is a centered
+%page number.
+这两个参数分别指定当前的页眉和页脚。
+\PlainTeX\ 输出例行程序将把页眉放在各页顶部,页脚放在各页底部。
+默认的页眉为空,而默认的页脚为居中的页码。
+
+%The headline and footline should both
+%be as wide as |\hsize| (use |\hfil|, \xref{\hfil}, for this
+%if necessary).
+%You should always include a font-setting command in these lines, since
+%the current font is unpredictable when \TeX\ is calling the
+%output routine. If you don't set the font explicitly,
+%you'll get whatever font \TeX\ was using when it broke the page.
+页眉和页脚的宽度应该和 |\hsize| 相等(必要时可以用 |\hfil|,\xref{\hfil})。
+在页眉和页脚中你永远应该加上字体设定命令,
+因为你无法预知 \TeX\ 调用输出例行程序时的当前字体。
+如果你不明确指明字体,\TeX\ 将使用分页时所用的字体。
+
+%You shouldn't try to use |\headline| or |\footline|
+%to produce multiline headers or footers.
+%Although \TeX\ won't complain, it will give you something that's very ugly.
+%See \xrefpg{bighead} for a method of creating multiline headers or
+%footers.
+不要试图用 |\headline| 或 |\footline| 生成多行的页眉或页脚。
+即使 \TeX\ 不会报错,它也只会出很难看的结果。
+在\xrefpg{bighead}中有生成多行页眉或页脚的方法。
+\example
+\headline = {\tenrm My First Reader\hfil Page \folio}
+|
+\produces
+\pageno = 10
+\line{\tenrm \noindent My First Reader\hfil Page \folio}
+\par ({\it at the top of page \folio}\/)
+\nextexample
+\footline = {\tenit\ifodd\pageno\hfil\folio
+ \else\folio\hfil\fi}
+% Produce the page number in ten-point italic at
+% the outside bottom corner of each page.
+|
+\endexample\enddesc
+
+%\secondprinting{\vfill\eject}
+
+
+%==========================================================================
+%\subsection {Marks}
+\subsection {标记}
+
+\begindesc
+\cts mark {\rqbraces{\<text>}}
+\explain
+%\bix^^{marks}
+%This command causes \TeX\ to append a mark
+%containing \<mark text>
+%to whatever list it is currently constructing.
+%Generally you shouldn't use |\mark| within an
+%``inner'' construct such as a math formula or a \minref{box}
+%you've built with an |\hbox|, |\vbox|, or |\vtop| command, because
+%\TeX\ won't see the mark when it's constructing the main box of the page. But
+%if you use |\mark| in ordinary horizontal \minref{mode}
+%or directly in an hbox that's part of the main vertical list,
+%the mark migrates out
+%to the main \minref{vertical list}.
+%See \knuth{pages~259--260} for examples showing how |\mark| can be used.
+\bix^^{标记}
+此命令让 \TeX\ 添加内容为 \<mark text> 的标记到当前正构造的列表中。
+一般地,此标记命令不应该在 “内部”构造中使用,
+例如数学公式或者用 |\hbox|、|\vbox| 或 |\vtop| 构造的\minref{盒子}。
+这是因为 \TeX\ 构造页面主盒子时将看不到这样的标记。
+但是,若你在普通水平\minref{模式}中用 |\mark|,
+或者在主竖直列的 hbox 中直接使用 |\mark|,
+该标记将会被转移到主\minref{竖直列}。
+在\knuth{第~259--260~页}中有如何使用 |\mark| 的例子。
+\enddesc
+
+\begindesc
+\cts firstmark {}
+\cts botmark {}
+\cts topmark {}
+\explain
+%These commands expand to the mark text in an item generated by an earlier
+%^|\mark| command.
+%The mark text has the form of a token list.
+%\TeX\ sets the values of these commands when it
+%finishes placing the contents of a page into ^|\box255|,
+%just before calling the \minref{output routine}
+%as part of its \minref{page break}ing actions. \TeX\ determines
+%these values as follows:
+%\ulist\compact
+%\li |\firstmark| contains the tokens of the first mark on the page.
+%\li |\botmark| contains the tokens of the last mark on the page.
+%\li |\topmark| contains the tokens of the mark that is in effect at
+%the very top of the page.
+%That mark is the last mark
+%that \emph{preceded} the page,
+%i.e., the |\botmark| of the previous page.
+%It is empty if no marks preceded the page.
+%\endulist
+%\noindent
+%If a page has no marks on it, \TeX\ will set |\firstmark| and |\botmark| to
+%the same mark as |\topmark|, i.e., the most recent preceding mark.
+%The table at the bottom of \knuth{page~258} illustrates the relation among
+%|\firstmark|, |\botmark|, and |\topmark|.
+这些命令展开为之前用 ^|\mark| 生成的标记项的标记文本。
+标记文本以记号列形式表示。
+执行分页工作时,\TeX\ 需要将页面内容放入 ^|\box255|,
+然后调用\minref{输出例行程序};
+在这两个步骤之间 \TeX\ 设定这些命令的值如下:
+\ulist\compact
+\li |\firstmark| 包含页面第一个标记的记号列。
+\li |\botmark| 包含页面最后一个标记的记号列。
+\li |\topmark| 包含紧跟在页面上边的那个标记的记号列。
+这个标记就是\emph{上一个}页面的最后一个标记,即上一页的 |\botmark|。
+如果上一页没有标记此命令为空。
+\endulist
+\noindent
+如果此页面没有任何标记,\TeX\ 设定 |\firstmark| 和 |\botmark| 都等于 |\topmark|,
+即前面最近的那个标记。
+\knuth{第~258~页}底部的表格说明了 |\firstmark|、|\botmark| 和 |\topmark| 这三者的关系。
+\enddesc
+
+\begindesc
+\cts splitfirstmark {}
+\cts splitbotmark {}
+\explain
+%^^{marks//for split lists}
+%These commands expand to the ^{mark text} generated by an earlier
+%^|\mark| command that produced an item in the item list of a vbox $V$.
+%The mark text has the form of a token list.
+%When \TeX\
+%splits $V$ in response to a ^|\vsplit| command (\xref \vsplit),
+%it sets the values of these commands as follows:
+%\ulist\compact
+%\li |\splitfirstmark| contains the tokens of the first mark in
+%the item list of $V$.
+%\li |\splitbotmark| contains the tokens of the last mark in
+%the item list of $V$.
+%\endulist
+%These commands produce no tokens if there was no preceding |\vsplit|,
+%or if the most recent preceding |\vsplit| didn't contain any marks.
+%\eix^^{marks}
+^^{标记//用于分割列表}
+这两个命令展开为之前用 ^|\mark| 在竖直盒子 $V$ 中生成的标记项的标记文本。
+标记文本以记号列形式表示。
+当你用 ^|\vsplit| 命令(\xref \vsplit )分割 $V$ 时,
+\TeX\ 按如下方式设定这两个命令的值:
+\ulist\compact
+\li |\splitfirstmark| 包含 $V$ 中第一个标记的记号列。
+\li |\splitbotmark| 包含 $V$ 中最后一个标记的记号列。
+\endulist
+如果没有 |\vsplit| 命令,或者前面最近的 |\vsplit| 不包含任何标记,
+这两个命令不生成记号列。
+\eix^^{标记}
+\enddesc
+
+%==========================================================================
+%\section {Insertions}
+\section {插入项}
+
+%\subsection {Footnotes}
+\subsection {脚注}
+
+\begindesc
+\easy\cts footnote {\<argument$_1$> \<argument$_2$>}
+\cts vfootnote {\<argument$_1$> \<argument$_2$>}
+\explain
+%These commands produce footnotes.
+%\<argument$_1$> is the ``^{reference mark}''
+%for the footnote and \<argument$_2$> is its text.
+%The text can be several paragraphs long if necessary and can contain
+%constructs such as math displays, but it shouldn't contain any
+%\minref{insertion}s (such as other footnotes).
+这两个命令用于生成脚注。
+其中 \<argument$_1$> 是脚注的“^{参考符号}”,
+而 \<argument$_2$> 是脚注文本。
+脚注文本必要时可以包含多个段落,也可以包含陈列公式等其他构造,
+但不应该包含任何\minref{插入项}(比如其他脚注)。
+
+%You shouldn't use these commands inside a subformula of a math formula,
+%in a box within a box being contributed to a page,
+%or in an insertion of any kind.
+%If you're unsure whether these restrictions apply, you can be safe by
+%only using |\footnote| and |\vfootnote| directly within a paragraph or
+%between paragraphs.
+在数学公式的子公式中,或者组成页面的盒子的子盒子中,
+或者任何形式的插入项中,你都不应该使用这些命令。
+如果你不确定这些限制出现在哪里,为安全起见,
+你可以只在段落内或者段落间直接使用 |\footnote| 和 |\vfootnote|。
+
+%These restrictions aren't as severe as they seem because you can use
+%|\vfootnote| to footnote most anything.
+%Both |\foot!-note| and |\vfoot!-note| insert the reference mark in front of the
+%footnote itself, but |\vfoot!-note| doesn't insert the reference mark into the
+%text.
+%Thus, when you use |\vfoot!-note| you can
+%explicitly insert the reference mark
+%wherever it belongs without concern about the context
+%and place the |\vfootnote| in the next paragraph.
+%If you find that the footnote lands on
+%the page following the one where it belongs, move the |\vfootnote| back
+%to the previous paragraph.
+%There are rare circumstances where you'll need to
+%alter the text of your document in order to get a footnote to appear on
+%the same page as its reference mark.
+这些限制没看起来那么严重,因为你可以用 |\vfootnote| 命令添加几乎任何内容的脚注。
+|\foot!-note| 和 |\vfoot!-note| 都会在脚注前面插入参考符号,
+区别在于 |\vfoot!-note| 不会在正文中插入参考符号。
+因此,你可以不用考虑上下文的限制,
+显式地将参考符号放到它应该在的地方,然后在下一个段落使用 |\vfootnote| 命令。
+这可能会导致脚注跑到下一页去,此时你可以将 |\vfootnote| 命令移动到上一个段落中。
+在极少情况下,你需要修改文档正文,以让脚注和参考符号出现在同一页中。
+\example
+To quote the mathematician P\'olya is a ploy.\footnote
+*{This is an example of an anagram, but not a strict one.}
+|
+\produces
+To quote the mathematician P\'olya is a ploy.*
+\par\line{\hskip .5in \vdots\hfil}
+\nointerlineskip \bigskip
+\footnoterule\par\parindent = 12pt
+\textindent{*}This is
+an example of an anagram, but not a strict one.
+\endexample
+\example
+$$f(t)=\sigma\sigma t\;\raise 1ex \hbox{\dag}$$
+\vfootnote \dag{The $\sigma\sigma$ notation was explained in
+the previous section.}
+|
+\produces
+$$f(t)=\sigma\sigma t\>\raise 1ex \hbox{\dag}$$
+\par\line{\hskip .5in \vdots\hfil}
+\nointerlineskip \bigskip
+\footnoterule\par\parindent = 12pt
+\textindent{\dag}{The $\sigma\sigma$ notation was explained in
+the previous section.}
+\endexample
+\enddesc
+
+%==========================================================================
+%\subsection {General insertions}
+\subsection {一般插入项}
+
+%\begindesc
+%\bix^^{insertions//commands for}
+%\cts topinsert {\<vertical mode material> {\bt \\endinsert}}
+%\cts midinsert {\<vertical mode material> {\bt \\endinsert}}
+%\cts pageinsert {\<vertical mode material> {\bt \\endinsert}}
+%\explain
+%These commands produce different forms of insertions that
+%instruct
+%(or allow) \TeX\ to relocate the \<vertical mode material>:
+%\ulist
+%\li |\topinsert| attempts to put the material at the top of the current page.
+%If it won't fit there, |\topinsert|
+%will move the material to the next available top of page.
+%\li |\midinsert| attempts to put the material at the current position.
+%If it won't fit there, |\midinsert|
+%will move the material to the next available top of page.
+%\li |\pageinsert| puts the material by itself on the next page.
+%To avoid an underfull page, be sure to end the inserted material with
+%|\vfil| or fill out the excess space some other way.
+%% Knuth doesn't say this, but I tried an experiment that verified it.
+%% Nor does he say explicitly that an insertion does a \par.
+%\endulist
+%\noindent
+%The \<vertical mode material>
+%is said to be ``floating'' ^^{floating material} because \TeX\
+%can move it from one place to another.
+%Insertions are very useful for material such as figures and tables because
+%you can position such material where you want it without knowing where the
+%page breaks will fall.
+\begindesc
+\bix^^{插入项//用于插入项的命令}
+\cts topinsert {\<vertical mode material> {\bt \\endinsert}}
+\cts midinsert {\<vertical mode material> {\bt \\endinsert}}
+\cts pageinsert {\<vertical mode material> {\bt \\endinsert}}
+\explain
+这些命令生成不同形式的插入项,
+它们指示(或者允许)\TeX\ 重新放置 \<vertical mode material>:
+\ulist
+\li |\topinsert| 试图将内容放在当前页的顶部。
+如果那里放不下,|\topinsert| 将把该内容移动到顶部可放下的下一个页面。
+\li |\midinsert| 试图将内容放在当前位置,
+如果当前位置放不下,|\midinsert| 将把该内容移动到顶部可放下的下一个页面。
+\li |\pageinsert| 将把内容单独放在下一页。
+为免得到松散页面,不要忘记在内容最后用 |\vfil| 命令或者其他方式填满页面。
+% Knuth doesn't say this, but I tried an experiment that verified it.
+% Nor does he say explicitly that an insertion does a \par.
+\endulist
+\noindent
+由于 \TeX\ 可以移动\<vertical mode material>的位置,我们称它为“浮动体”。^^{浮动体}
+插入项对于图形和表格非常有用,
+因为你可以将它们放在所需的地方,而不用管哪里会分页。
+
+%Each of these commands implicitly ends the current paragraph, so
+%you should use them only between paragraphs.
+%You should not use them within a box or within another insertion.
+%If you have several insertions competing for
+%the same space, \TeX\ will retain their relative order.
+这些命令每个都会结束当前段落,因此你应该仅在段落之间使用它们。
+你也不要在盒子内部或者另一个插入项内部使用它们。
+如果有多个插入项要放在同一个位置,\TeX\ 将保持它们的先后顺序。
+\example
+\pageinsert
+% This text will appear on the following page, by itself.
+This page is reserved for a picture of the Queen of Hearts
+sharing a plate of oysters with the Walrus and
+the Carpenter.
+\endinsert
+|
+\endexample
+\enddesc
+
+\begindesc
+\cts endinsert {}
+\explain
+%This command ends an insertion started by
+%|\topinsert|, |\midinsert|, or |\pageinsert|.
+此命令结束由 |\topinsert|、|\midinsert| 或 |\pageinsert| 命令开始的插入项。
+\enddesc
+
+\begindesc
+\cts insert {\<number> \rqbraces{\<vertical mode material>}}
+\explain
+%\minrefs{insertion}
+%This primitive command provides the
+%underlying mechanism for constructing insertions, but
+%it is hardly ever used outside of a \minref{macro} definition.
+%The definitions of the
+%|\foot!-note|, |\vfoot!-note|,
+%|\top!-insert|, |\mid!-insert|, and |\page!-insert| commands are
+%all built around |\insert|.
+%^^|\topinsert|
+%^^|\midinsert| ^^|\pageinsert| ^^|\footnote| ^^|\vfootnote|
+\minrefs{insertion}
+这个原始命令提供了构造插入项的内部机制,
+但除了在定义\minref{宏}时会用到,其他时候很少用到它。
+|\foot!-note|、|\vfoot!-note|、|\top!-insert|、|\mid!-insert| 和
+|\page!-insert| 命令的定义都建立在 |\insert| 命令之上。
+^^|\topinsert|
+^^|\midinsert| ^^|\pageinsert| ^^|\footnote| ^^|\vfootnote|
+
+%When you design insertions for a document, you should assign a different
+%integer code\footnote
+%{\texbook{} uses the term ``class'' for a code.
+%We use a different term to avoid confusion with the other meaning of
+%``class'' (\xref{class}).}
+%$n$ to each kind of insertion,
+%using the ^|\newinsert| command (\xref{\@newinsert}) to obtain the
+%integer codes.
+%The |\insert| command itself appends the \<vertical mode material>
+%to the current horizontal or \minref{vertical list}.
+%Your \minref{output routine} is responsible for
+%moving the inserted material from where it resides in |\box|$\,n$
+%to an output page.
+%^^{output routine}
+设计文档的插入项时,不同的插入项需要分配不同的整数代码\footnote
+{\texbook{} 用“类”这个术语表示此代码。
+为避免和“类”(\xref{类})的其他意思混淆,我们用不同的术语。}
+$n$,这个代码可以用 ^|\newinsert| 命令(\xref{\@newinsert})得到。
+|\insert|命令本身仅添加 \<vertical mode material> 到当前水平列或\minref{竖直列}。
+而\minref{输出例行程序}负责移动|\box|$\,n$中的插入内容到输出页面。
+^^{输出例行程序}
+
+%\TeX\ groups together all insertions having the same code
+%number. Each insertion
+%code $n$ has four \minref{register}s associated with it:
+%\ulist
+%\li |\box|$\,n$ is where \TeX\ accumulates the material for insertions
+%with code $n$. When \TeX\ breaks a page, it puts into |\box|$\,n$
+%as much insertion $n$ material as will fit on the page.
+%Your output routine should then move this material to the actual page.
+%You can use ^|\ifvoid| \ctsref{\@ifvoid}
+%to test if there is any material in |\box|$\,n$.
+%If not all the material fits, \TeX\ saves the leftovers for the next page.
+%\li |\count|$\,n$ is a magnification factor $f.$ When \TeX\ is computing
+%the vertical space occupied on the page
+%by insertion $n$ material, it multiplies the
+%vertical extent of this material by $f/1000$.
+%Thus you would ordinarily set $f$ to $500$ for a double-column insertion
+%and to $0$ for a marginal~note.
+%\li |\dimen|$\,n$ specifies the maximum amount
+%of insertion $n$ material that \TeX\ will put on a single page.
+%\li |\skip|$\,n$ specifies extra space that \TeX\ allocates on the page
+%if the page contains any insertion $n$ material.
+%This space is in addition to the space occupied by the insertion itself.
+%For example, it would account for the space on a page above the footnotes
+%(if there are~any).
+%\endulist
+%\noindent
+%\TeX\ sets |\box|$\,n$, and you should set the other three registers
+%so that \TeX\ can correctly compute the vertical space required by the
+%insertion.
+%See \knuth{pages~122--125} for further details of how \TeX\ processes this
+%command and of how insertions interact with page breaking.
+%\xrdef{endofinsert}
+\TeX\ 将所有插入项按照它们的代码分组。每个插入代码关联四个\minref{寄存器}:
+\ulist
+\li |\box|$\,n$ 给 \TeX\ 用于累积第 $n$ 种插入内容。
+\TeX\ 分页时会尽可能多地往 |\box|$\,n$ 中放入第$n$ 种插入项。
+然后输出例行程序将把这些内容移动了实际页面上。
+你可以用 ^|\ifvoid| 命令\ctsref{\@ifvoid}检查 |\box|$\,n$ 中是否有任何内容。
+如果不能放下全部内容,\TeX\ 将把剩下内容留到下一页。
+\li |\count|$\,n$ 为放大因子 $f$。
+\TeX\ 计算第$n$种插入项所占用的页面纵向空间时,将把插入内容的纵向长度乘以$f/1000$。
+因此对双栏插入项通常设 $f$ 为 $500$,而对边注项设为 $0$。
+\li |\dimen|$\,n$ 设定每页放置的第$n$种插入项的最大数目。
+\li |\skip|$\,n$ 设定页面包含第 $n$ 种插入项时 \TeX\ 添加的额外间隔。
+这个间隔不包含该插入项本身占用的空间。
+例如,当页面包含脚注时,就会用到此间隔。
+\endulist
+\noindent
+\TeX\ 只设定 |\box|$\,n$,你需要设定其他三个寄存器,
+以让 \TeX\ 正确计算插入项所需的竖直空间。
+\knuth{第~122--125~页} 中详细介绍了 \TeX\ 如何处理此命令,
+以及插入项和分页方式之间的关系。
+\xrdef{endofinsert}
+\enddesc
+
+%\see |\floatingpenalty| (\xref \floatingpenalty).
+%\eix^^{insertions//commands for}
+\see |\floatingpenalty| (\xref \floatingpenalty).
+\eix^^{插入项//用于插入项的命令}
+
+
+%==========================================================================
+%\section{Modifying the output routine}
+\section{修改输出例行程序}
+
+%\bix^^{output routine}
+%\begindesc
+%\cts output {\param{token list}}
+%\explain
+%This parameter contains the current \minref{output routine}, i.e.,
+%the token list that \TeX\ expands when it finds a page break.
+%\TeX\ puts the page into ^|\box255|, so |\output| is responsible
+%for doing something with |\box255|---either shipping it out or
+%putting it somewhere else.
+%The output routine is also responsible for attaching things such as
+%headers and footers.
+%\enddesc
+\bix^^{输出例行程序}
+\begindesc
+\cts output {\param{token list}}
+\explain
+这个参数包含了当前的 \minref{输出例行程序},
+也就是 \TeX\ 当发现一个断页点的时候会展开的一个符号列表。
+\TeX\ 把当前页面放入 ^|\box255|,所以 |\output| 负责对 |\box255| 进行处理%
+——不管是把它输出到 dvi 还是把它放到别的什么地方去。
+输出例行程序也负责把页眉和页脚附加到页面上。
+\enddesc
+
+%\begindesc
+%\cts plainoutput {}
+%\explain
+%This command invokes \plainTeX's output routine.
+%^^{output routine//default in \plainTeX}
+%\PlainTeX\ defines ^|\output| as
+%a token list containing the single token |\plainoutput|.
+%\enddesc
+
+\begindesc
+\cts plainoutput {}
+\explain
+这个命令调用 \plainTeX\ 的输出例行程序。
+^^{输出例行程序//\plainTeX\ 的默认程序}
+\PlainTeX\ 把 ^|\output| 定义为一个仅仅包含 |\plainoutput| 的符号列表。
+\enddesc
+
+
+%\begindesc
+%\cts shipout {\<box>}
+%\explain
+%This command instructs \TeX\ to send \<box> to the \dvifile.
+%^^{\dvifile//receives boxes from \b\tt\\shipout\e}
+%\TeX\ expands any |\write| command in \<box> as part of |\shipout|.
+%^^|\write//expanded during {\tt\\shipout}|
+%The principal use of |\shipout| is in the output routine, but you can
+%use it anywhere.
+%\enddesc
+
+\begindesc
+\cts shipout {\<box>}
+\explain
+这个命令让 \TeX\ 把 \<box> 输出到 \dvifile.
+^^{\dvifile//接收 \b\tt\\shipout\e 的盒子}
+\TeX\ 在 |\shipout| 时,把 \<box> 中的任何 |\write| 命令进行展开。
+^^|\write// 在 {\tt\\shipout} 时进行展开|
+|\shipout| 的主要用途是在输出例行程序中,不过你可以在任何其他地方使用这个命令。
+\enddesc
+
+
+%\begindesc
+%\cts deadcycles {\param{number}}
+%\explain
+%This parameter contains the number of times that \TeX\ has initiated
+%the \minref{output routine} since the last time it did a
+%^^|\shipout| |\ship!-out|.\footnote{
+%More precisely, \TeX\ sets |\dead!-cyles| to $0$ whenever it executes
+%|\ship!-out|
+%and increments it by $1$ whenever it executes |\output|.}
+%If |\deadcycles| gets too big, you've probably gotten
+%\TeX\ into a loop, e.g., one where the page builder is trying the same page
+%break over and over again.
+%\enddesc
+
+\begindesc
+\cts deadcycles {\param{number}}
+\explain
+这个参数包含这 \TeX\ 在上次 ^^|\shipout| |\ship!-out|
+后已经初始化的\minref{输出例行程序}的个数。
+\footnote{更加准确地说, \TeX\ 在执行 |\ship!-out| 的时候,
+把 |\dead!-cycles| 归 $0$,然后每次执行 |\output| 的时候把它增加 $1$。}
+如果 |\deadcycles| 变得太大,那你很有可能把 \TeX\ 弄死循环了,
+也就是说,循环往复地对同一个页面进行分页操作。
+\enddesc
+
+
+%\begindesc
+%\cts maxdeadcycles {\param{number}}
+%\explain
+%If the value of |\deadcycles| exceeds the value of |\maxdeadcycles|,
+%\TeX\ assumes that the output routine has gotten into a loop.
+%\TeX\ then complains and runs its own simple output routine,
+%equivalent to |\shipout!allowbreak\box255|,
+%that is likely to break the loop.
+%\PlainTeX\ sets |\maxdeadcycles| \hbox{to $25$}.
+%\enddesc
+
+\begindesc
+\cts maxdeadcycles {\param{number}}
+\explain
+如果 |\deadcycles| 超过了 |\maxdeadcycles|,那 \TeX\ 就会假定输出例行程序被用户死循环了,
+\TeX\ 这个时候就会报错,并且执行它自己默认的简单输出例行程序,也就是 |\shipout!allowbreak\box255|,
+以期望从循环中跳出。\PlainTeX\ 把 |\maxdeadcycles| 设置为 \hbox{$25$}。
+\enddesc
+
+%\begindesc
+%\cts outputpenalty {\param{number}}
+%\explain
+%\TeX\ sets this parameter when it breaks a page. If the breakpoint was at a
+%\minref{penalty} item, \TeX\ removes the penalty item and
+%sets |\outputpenalty| to the penalty value at
+%the breakpoint; otherwise it sets |\outputpenalty| \hbox{to $0$}.
+%
+%Suppose that you are undoing a page break
+%in order to break the page at a different place than the one that \TeX\
+%has just chosen. In order to reconstruct the page, you need to recreate
+%the penalty at \TeX's chosen breakpoint.
+%You can accomplish this with the command
+%|\penalty!allowbreak\outputpenalty|.
+%\enddesc
+
+\begindesc
+\cts outputpenalty {\param{number}}
+\explain
+\TeX\ 在断页的时候设置这个参数。
+如果断点是在一个 \minref{惩罚} 的项目上,\TeX\ 就会移除这个惩罚,
+然后把 |\outputpenalty| 设置成断点处的值, 否则 |\outputpenalty| 就被设成 \hbox{$0$}。
+
+如果你希望在 \TeX\ 选择的断点之外的的其他地方断页,而不在该断点处断页,
+那么在重构这个页面时,你就需要在 \TeX\ 选择的断点处重新设置这个惩罚。
+你可以通过 |\penalty!allowbreak\outputpenalty| 来达到这个目的。
+\enddesc
+
+
+%\begindesc
+%\cts holdinginserts {\param{number}}
+%\explain
+%If this parameter is greater than $0$ when \TeX\
+%is processing a page break, \TeX\ will refrain from processing insertions.
+%Setting this parameter to $1$
+%can be useful when you're writing an output routine
+%that needs to reprocess the contents of the page, e.g.,
+%an output routine that uses a value of |\vsize| (\xref \vsize) different from
+%the one used by the page builder.
+%
+%\eix^^{output routine}
+%\enddesc
+
+\begindesc
+\cts holdinginserts {\param{number}}
+\explain
+
+当 \TeX\ 在处理一个断页时,这个参数如果大于 $0$, 那么 \TeX\ 就会阻止处理插入。
+当你写一个输出例行程序的时候,如果你希望重新处理该页的内容,
+(例如输出例行程序本身用的 |\vsize| (\xref \vsize) 和断页程序用的并非相同值),
+那么把这个参数设为 $1$ 就会很有用。
+
+\eix^^{输出例行程序}
+\enddesc
+
+
+%==========================================================================
+%\section {Splitting vertical lists}
+\section {分割竖直列表}
+
+%\begindesc
+%\cts vsplit {\<number> {\bt to} \<dimen>}
+%\explain
+%This command causes \TeX\ to split the \minref{box} numbered
+%\<number>, which we'll call $B_2$, into two parts.
+%It uses the same algorithm that it would use if $B_2$ was a page
+%and it was breaking that page;
+%the division point then corresponds to the page break that it would find.
+%The box $B_2$ must be a vbox, not an hbox.
+%% we avoid starting the previous sentence with a symbol, a copyediting no-no.
+%\TeX\ puts the material preceding the division point into
+%another box $B_1$ and leaves the material after the division point in $B_2$.
+%The |\vsplit| command then produces $B_1$.
+%Normally you'd assign $B_1$ to a different
+%box register, as in the example below.
+%If the division point is at the end of $B_2$,
+%$B_2$ will be empty after the |\vsplit|.
+
+\begindesc
+\cts vsplit {\<number> {\bt to} \<dimen>}
+\explain
+这个命令使得 \TeX\ 把寄存器中编号为 \<number> 的\minref{盒子} $B_2$ 切割成两个部分。
+如果 $B_2$ 是一个页面,那这个命令会使用相同的算法来把这个页面分为两部分;
+这种情况下,分割处就是断页的地方。
+$B_2$这个盒子必须是个竖直盒子,不是水平盒子。
+\TeX\ 把从开头到分割处的部分放到另一个盒子 $B_1$ 中,而把分割处到结尾的部分放到 $B_2$ 中。
+然后 |\vsplit| 就输出了 $B_1$ 这个盒子。
+一般情况下,你会用类似下面例子的方式,把 $B_1$ 盒子指定到另一个盒子寄存器中。
+如果分割处恰好是 $B_2$ 盒子的结尾部分,那 $B_2$ 盒子就会在 |\vsplit| 后变成一个空盒子。
+
+
+%\TeX\ employs its usual page-breaking algorithm
+%^^{page breaks//in split lists}
+%for the split.
+%It uses \<dimen> for ^|\pagegoal|, the desired height of $B_1$.
+%The vertical extent of $B_1$ may not be exactly
+%\<dimen> because \TeX\ may not be able to achieve its page goal perfectly.
+%\TeX\ does not consider insertions in calculating the split,
+%so insertions in the original vertical list of $B_2$ will be retained
+%but won't affect the split point.
+
+\TeX\ 使用它一贯的断页算法来分割这个竖直盒子。
+它使用 \<dimem> 的长度来指定 $B_1$ 盒子需要的高度 ^|\pagegoal|。
+而$B_1$ 的竖直长度未必就一定是 \<dimem>,因为 \TeX\ 不一定能完美地达到其分页的目标。
+\TeX\ 在计算这个竖直分割的时候,不考虑插入,因此 $B_2$ 插入的原本的竖直列表依然会被保留,但并不会受到分割的影响。
+
+
+%\example
+%\setbox 20 = \vsplit 30 to 7in
+%% Split off the first seven inches or so of material from
+%% box 30 and place that material in box 20.
+%|
+%\endexample
+%\enddesc
+
+\example
+\setbox 20 = \vsplit 30 to 7in
+% 把30号盒子截去7英寸,并放到20号盒子中。
+|
+\endexample
+\enddesc
+
+
+%\begindesc
+%\cts splitmaxdepth {\param{dimen}}
+%\explain
+%This parameter specifies the
+%maximum allowable depth of a box resulting from a |\vsplit|.
+%|\splitmaxdepth| plays the
+%same role that ^|\maxdepth| (\xref \maxdepth) plays for a page.
+%\enddesc
+
+\begindesc
+\cts splitmaxdepth {\param{dimen}}
+\explain
+此参数指定|\vsplit|产生的盒子的最大允许深度。
+|\splitmaxdepth| 在盒子中和 ^|\maxdepth| (\xref \maxdepth) 在页面中扮演的角色相同。
+\enddesc
+
+
+%\begindesc
+%\cts splittopskip {\param{glue}}
+%\explain
+%This parameter specifies the glue that \TeX\ inserts at the top of
+%a box resulting from a |\vsplit|.
+%|\splittopskip| plays the
+%same role that ^|\topskip| (\xref \topskip) plays for a page.
+%\enddesc
+
+\begindesc
+\cts splittopskip {\param{glue}}
+\explain
+这个参数指定 \TeX 在 |\vsplit| 产生的盒子的头部插入的粘连。
+|\splittopskip| 在盒子中和 ^|\topskip| (\xref \topskip) 在页面中扮演的角色相同。
+\enddesc
+
+
+%\see |\splitbotmark|, |\splitfirstmark| (\xref \splitfirstmark).
+
+\see |\splitbotmark|, |\splitfirstmark| (\xref \splitfirstmark).
+
+\enddescriptions
+
+\ifoldeplain\else\ifcompletebook\else
+\vskip4em{\sectionfonts\leftline{本章索引}}
+\readindexfile{i}
+\fi\fi
+
+\endchapter \byebye