答案1
您可以将一条double
双线与另一条double
线一起使用postaction
。
\documentclass[tikz,border=3mm]{standalone}
\begin{document}
\begin{tikzpicture}[nodes={draw,thick,fill=yellow!80!black,minimum size=1cm,
font=\sffamily\bfseries},
quadruple/.style={double distance=#1-\pgflinewidth,thick,
postaction={draw,thick,double distance=#1/3-\pgflinewidth}},
quadruple/.default=1em]
\path (0,0) node (A) {A} (3,3) node (B){B};
\draw[quadruple] (A) -- ++ (1,0) |- (B);
\end{tikzpicture}
\end{document}