※ 引述《rareone (拍玄)》之铭言：
: http://imgur.com/a/9WUtP
: 在看具体数学的时候看到这种方块式子令人眼睛为之一亮
: 我也想在写讲义的时候插入这类的图
: 可是又不想直接引用图片
: 像这类的图，以我目前对latex的认知 关键字难找
: 恳请大家给我一些意见 关键字也好 拜托了 >_<
: 找到我要的答案 会发100p币（税前）作为一点小心意，谢谢
在 Knuth 老大排版的时候是这样处理的：
【定义符号与指令】
\unitlength=3pt
\def\domi{\beginpicture(0,2)(0,0) % identity
\put(0,0){\line(0,1){2}}
\endpicture}
\def\domI{\beginpicture(0,2)(0,0) % identity when isolated
\put(0,-.1){\line(0,1){2.2}}
\endpicture}
\def\domv{\beginpicture(1,2)(0,0) % vertical without left edge
\put(1,0){\line(0,1){2}}
\put(0,0){\line(1,0){1}}
\put(0,2){\line(1,0){1}}
\endpicture}
\def\domhh{\beginpicture(2,2)(0,0) % two horizontals without left edge
\put(2,0){\line(0,1){2}}
\put(0,0){\line(1,0){2}}
\put(0,1){\line(1,0){2}}
\put(0,2){\line(1,0){2}}
\endpicture}
\def\Domh{\beginpicture(3,1)(-.5,0) % horizontal, stand-alone
\put(2,0){\line(0,1){1}}
\put(0,0){\line(0,1){1}}
\put(0,0){\line(1,0){2}}
\put(0,1){\line(1,0){2}}
\endpicture}
\def\Domv{\beginpicture(2,2)(-.5,0) % vertical, stand-alone
\put(0,0){\line(0,1){2}}
\put(1,0){\line(0,1){2}}
\put(0,0){\line(1,0){1}}
\put(0,2){\line(1,0){1}}
\endpicture}
【实际用在排版】
The null tiling $\,\domI\,$,
which is the multiplicative identity for our combinatorial arithmetic,
plays the part of~$1$, the usual multiplicative identity;
and $\domi\domv+\domi\domhh$ plays~$z$.
So we get the expansion
\begindisplay
{\hbox{\domI}\over\domI-\domi\domv-\domi\domhh}
&=\domI+(\,\domi\domv+\domi\domhh\,)+
(\,\domi\domv+\domi\domhh\,)^2+
(\,\domi\domv+\domi\domhh\,)^3+\cdots\cr
&=\domI+(\,\domi\domv+\domi\domhh\,)+
(\,\domi\domv\domv+\domi\domv\domhh+\domi\domhh\domv+\domi\domhh\domhh\,)\cr
&\qquad+(\,\domi\domv\domv\domv+\domi\domv\domv\domhh
+\domi\domv\domhh\domv+\domi\domv\domhh\domhh
+\domi\domhh\domv\domv+\domi\domhh\domv\domhh
+\domi\domhh\domhh\domv+\domi\domhh\domhh\domhh\,)+\cdots\,.\cr
\enddisplay
This is $T$, but the tilings are arranged in a different order than
we had before. Every tiling appears exactly once in this sum;
for example, $\domi\domv\domhh\domhh\domv\domv\domhh\domv$
appears in the expansion of $(\,\domi\domv+\domi\domhh\,)^7$.
We can get useful information from this infinite sum by compressing it
down, ignoring details that are not of interest. For example, we
can imagine that the patterns become unglued and that the individual dominoes
commute with each other; then a term like
$\domi\domv\domhh\domhh\domv\domv\domhh\domv$ becomes $\Domv^4\Domh^6$,
because it contains four verticals and six horizontals. Collecting
like terms gives us the series
\begindisplay
T = \domI+\Domv+\Domv^2+\Domh^2+\Domv^3+2\Domv\Domh^2+\Domv^4+3\Domv^2\Domh^2
+\Domh^4+\cdots\,.
\enddisplay
The $2\Domv\Domh^2$ here represents
the two terms of the old expansion,
\domi\domv\domhh\ and~\domi\domhh\domv\kern1pt, that
have one vertical and two horizontal dominoes;
similarly $3\Domv^2\Domh^2$
represents the three terms
\domi\domv\domv\domhh\kern1pt, \domi\domv\domhh\domv\kern1pt, and
\domi\domhh\domv\domv\kern1pt.
We're essentially treating \Domv\ and~\Domh\ as ordinary (commutative)
variables.