如何编码该表？（可数集的并集）

Question

如何对可数集并集图示中的表格进行编码？

Answer 1

解决方案如下pstricks：

\documentclass{article}
\usepackage{mathtools}
\usepackage{pst-node, multido}

\begin{document}

\begin{spreadlines}{4ex}
\begin{alignat*}{5}
 A_1&=\{\Rnode{N1}{a_{11}}, &\qquad & \Rnode{N2}{a_{12}}, &\qquad & \Rnode{N6}{a_{13}}, &\qquad & \Rnode{N7}{a_{14}}, & \enspace & \dots\} \\
 A_2&=\{\Rnode{N3}{a_{21}},& & \Rnode{N5}{a_{22}},& & \Rnode{N8}{a_{23}},& & a_{24}, & & \dots\} \\
 A_3&=\{\Rnode{N4}{a_{31}},& & \Rnode{N9}{a_{32}},& & a_{33}, & & a_{34}, & & \dots\} \\
 A_4&=\{\Rnode{N10}{a_{41}},& & a_{42},& & a_{43},& & a_{44}, & & \dots\} \\
  & \phantom{ = \{\,} \Rnode{N11}{\phantom{a_{51}, }}
\psset{linewidth=0.6pt, arrows=->, arrowinset=0.12, nodesep=3pt}
\multido{\is=1+1,\it=2 +1}{10}{\ncline{N\is}{N\it}}
\end{alignat*}
\end{spreadlines}

\end{document} 

Answer 2

为了帮助您入门，这里有一个使用align*和的建议tikzmark：

\documentclass{article}
\usepackage{amsmath}
\usepackage{tikz}
\usetikzlibrary{tikzmark}
\begin{document}
\begin{align*}
A_{1} &= \{a_{11}, \tikzmarknode{1}{\rightarrow}\, a_{12}\} \\[6pt]
A_{2} &= \{\tikzmarknode{2}{a_{21}}, \rightarrow a_{22}\}
\end{align*}
\begin{tikzpicture}[remember picture, overlay]
\draw[-latex](1)--(2);
\end{tikzpicture}
\end{document}

Answer 3

与 leandriis 的回答（我刚才看到）中的策略相同，但更多屏幕截图的内容被重现。

\documentclass[fleqn]{article}
\usepackage{mathtools}
\usepackage{tikz}
\usetikzlibrary{tikzmark}
\usetikzlibrary{decorations.pathreplacing} 
\newcommand{\Cdotfill}{\leaders\hbox{$\,\cdot$}\hfill}
\newcommand{\aij}[1]{\tikzmarknode{a#1}{a_{#1}}}
\begin{document}
\begin{align*}
 A_1&=\{\aij{11},~~\aij{12},~~\aij{13},~~\aij{14},\dots\}\\[1em]
 A_2&=\{\aij{21},~~\aij{22},~~\aij{23},~~\aij{24},\dots\}\\[1em]
 A_3&=\{\aij{31},~~\aij{32},~~\aij{33},~~\aij{34},\dots\}\\[1em]
 A_4&=\{\aij{41},~~\aij{42},~~\aij{43},~~\aij{44},\dots\}
\begin{tikzpicture}[overlay,remember picture]
 \draw[decorate,decoration={show path construction,
    lineto code={\draw [->,shorten >=0.5ex,shorten <=0.5ex] 
    (\tikzinputsegmentfirst) -- (\tikzinputsegmentlast);}}]
    (a12) -- (a21) -- (a31) -- (a22) -- (a13) 
    (a42) -- (a33) -- (a24) (a34) -- (a43);
 \path[->,shorten >=0.5ex,shorten <=0.5ex] foreach \X in {1,2,3}
  {(a\X\the\numexpr5-\X) edge (a\the\numexpr\X+1\relax\the\numexpr4-\X)}
  (a41.south) edge ++ (0,-1.5em);
  \path[->] ([yshift=2pt]a11.east) edge ([yshift=2pt]a12.west) 
  ([yshift=2pt]a13.east) edge ([yshift=2pt]a14.west);
\end{tikzpicture}   \\[1em]
 \MoveEqLeft~\makebox[15em]{\Cdotfill}
\end{align*}
\end{document}