按照 Coxeter 的《正复多胞形 (1974)》设置短显示跳过

Question

我当时正在阅读 Coxeter 1974 年出版的《正则复多胞形》，不仅被书中的数学内容所震撼，还被书中优美的排版所打动。我尤其喜欢这样一个事实：显示方程在相对于上两行较短的前一行之后的垂直跳跃被设置为与标准显示方程的垂直跳跃相同。由于担心我的描述难以理解，我引用了该书第 54 页中的几段文字：

\abovedisplayshortskip我可以通过参考\abovedisplayskip和手动选择来模仿这种效果\baselineskip，但是有没有办法自动做到这一点？

Answer 1

除非“短线”的高度或深度过大，否则应该这样做：设置为与减去\abovedisplayshortskip相同。也应设置为等于。\abovedisplayskip\baselineskip\belowdisplayshortskip\belowdisplayskip

\documentclass{article}
\usepackage{amsmath}

\makeatletter
\g@addto@macro\normalsize{%
  \setlength\abovedisplayshortskip{\glueexpr\abovedisplayskip-\baselineskip}%
  \setlength\belowdisplayshortskip{\belowdisplayskip}%
}
\makeatother

\begin{document}

\section{With Coxeter's setting}

An arbitrary inversion yields a new diagram formed by $n+2$ points
on a circle, and arcs through pairs of them orthogonal to this circle.
If $X_sX_tX_uX_v$ is a convex quadrilateral, Ptolemy's theorem tells us
that
\[
X_sX_t.X_uX_v-X_sX_u.X_tX_v+X_sX_v.X_tX_u=0,
\]
suggesting the investigation of numbers $(s,t)$ (functions of integers
$s$~and~$t$) that satisfy
\[
(s,t)(u,v)+(s,u)(v,t)+(s,v)(t,u)=0
\]
(Coxeter~1963), p.~160). This functional equation provides the rule
for constructing our `modified frieze patterns'.

\section{Standard}

\setlength{\abovedisplayshortskip}{0pt plus 3pt}
\setlength{\belowdisplayshortskip}{6pt plus 3pt minus 3pt}

An arbitrary inversion yields a new diagram formed by $n+2$ points
on a circle, and arcs through pairs of them orthogonal to this circle.
If $X_sX_tX_uX_v$ is a convex quadrilateral, Ptolemy's theorem tells us
that
\[
X_sX_t.X_uX_v-X_sX_u.X_tX_v+X_sX_v.X_tX_u=0,
\]
suggesting the investigation of numbers $(s,t)$ (functions of integers
$s$~and~$t$) that satisfy
\[
(s,t)(u,v)+(s,u)(v,t)+(s,v)(t,u)=0
\]
(Coxeter~1963), p.~160). This functional equation provides the rule
for constructing our `modified frieze patterns'.

\end{document}

如果您计划在（或其他类似情况下）使用显示器\footnotesize，您还必须更新这些设置。