答案1
这非常简单pstricks
:
\documentclass{article}
\usepackage{amssymb, upgreek}
\usepackage{pst-node}
\begin{document}
\[ \Rnode{T}{\mathbf{\uptau}} \vee \lnot \in \Rnode{S1}{\square} \mathbf{A'}\in \Rnode{S2}{\square} \mathbf{A''}
\psset{linejoin=1, angle=90, nodesep=2pt}
\ncbar{T}{S1}\ncbar[armA=15pt]{T}{S2}\]%
\end{document}%