# How to create this simple model with arrow and text on the top?

How to create this simple model with arrow and text on the top ? Regards

Without a package and simple LaTeX commands:

\documentclass{article}
\unitlength=1cm
\newcommand\test[2]{%
\begin{picture}(3,2)
\put(0,0){\line(1,0){3}}     \put(0,2){\line(1,0){3}}
\put(1.5,0){\vector(1,2){1}} \put(1.5,0){\vector(-1,2){1}}
\put(0.45,2.1){#1}\put(2.35,2.1){#2}
\end{picture}}

\begin{document}
\test{G}{A}
\end{document}


Typically, we don't answer 'draw this for me' or similar questions, but I'm feeling nice.

You can use the TikZ package like so:

\documentclass{article}

\usepackage{tikz}
\tikzset{>=stealth}

\begin{document}
\begin{tikzpicture}
\draw (-0.5,0) -- (2.5,0) (-0.5,-2) -- (2.5,-2) ;
\draw [->] (0,0) node [anchor=south] {$$A$$} -- (1,-2) ;
\draw [->] (1,-2) -- (2,0) node [anchor=south] {$$G_1$$} ;
\end{tikzpicture}
\end{document}