$\newcommand{\MyTikzmark}[2]{ \tikz[overlay,remember picture,baseline] \node [anchor=base] (#1) {$#2$};} \newcommand{\DrawVLine}[3][]{ \begin{tikzpicture}[overlay,remember picture] \draw[shorten \lt =0.3ex, #1] (#2.north) -- (#3.south); \end{tikzpicture} } \newcommand{\DrawHLine}[3][]{ \begin{tikzpicture}[overlay,remember picture] \draw[shorten \lt =0.2em, #1] (#2.west) -- (#3.east); \end{tikzpicture} } \newcommand{\lt}{<} \newcommand{\gt}{>} \newcommand{\amp}{&}$