Half table border in Math (see example)

Question

I need like this half table border.

Please help me.

Answer 1

I solve my problem by this code:

\[\left| \!{\overline {\, 
 \begin{array}{l}
 {X_1}^{(1)}‎\hphantom{x}‎{\rm{  }}{X_2}^{(1)}‎\hphantom{x}{\rm{ }}{X_3}^{(1)}‎\hphantom{x}{\rm{ }}{X_4}^{(1)}‎\hphantom{xyz}‎\sim{1-e^{-t^2}}‎ \\ 
 {X_1}^{(2)}‎\hphantom{x}{\rm{ }}{X_2}^{(2)}‎\hphantom{x}{\rm{ }}{X_3}^{(2)}‎\hphantom{xyzwasda}‎\sim{1-e^{-2(t^{2}-x^{2})}}‎ \\ 
 \end{array} \,}} \right. \]‎‎‎‎

But if your math formula is simple, @Fran's answer is nice (This comment was little need to edit.)

\begin{tabular}{11|}\hline a & ‎b‎‎‎‎‎‎‎‎‎‎‎\\‎
c & d‎‎‎‎‎‎\\ ‎\end{tabular}‎

❤️ Thank's all users for their comments.

Answer 2

You can do with some help by array.

Since there are both complex superscripts and subscripts, I chose to issue \displaystyle in every cell of the array, which raises them a bit.

Second trick: (locally) increase the apparent height of the cells, in order to better separate them.

\documentclass{article}
\usepackage{amsmath}
\usepackage{array}

\begin{document}

\[
\setlength{\extrarowheight}{1.5ex} % more room
\begin{array}{ | *{4}{>{\displaystyle}l} @{\qquad} >{\displaystyle}l }
\hline
X_{1}^{(1)} & X_{1}^{(2)} & X_{1}^{(3)} & X_{1}^{(4)} & \sim 1-e^{-t^{2}} \\
X_{1}^{(1)} & X_{1}^{(2)} & X_{1}^{(3)} &             & \sim 1-e^{-2(t^{2}-x^{2})} \\
\end{array}
\]

\end{document}

Answer 3

You can simplfiy your code in this way:

\documentclass{article}
\begin{document}
\[
\begin{array}{|cccc@{\hspace{2em}}l}
\hline\\[-1em]
X_1^{(1)} & X_2^{(1)} & X_3^{(1)} & X_4^{(1)} & ‎\sim 1-e^{-t^2}‎  \\[1ex]
X_1^{(1)} & X_2^{(2)} & X_3^{(2)} & & \sim 1-e^{-2(t^{2}-x^{2})}  \\
\end{array} 
\]
\end{document}