\documentclass{article}
\usepackage{com.braju.graphicalmodels}
\usepackage{amsmath}
% \special{papersize=40mm,80mm}
% \setlength{\pdfpagewidth}{40mm}
% \setlength{\pdfpageheight}{80mm}
% \usepackage[vcentering,dvips]{geometry}
% \geometry{papersize={80mm,120mm},total={80mm,120mm},margin=0mm}



\catcode`\@=11%

\pagestyle{empty}

\begin{document}
\TeXtoEPS

\LARGE
\psset{unit=10mm,arrowscale=1.5,linewidth=1.5pt}

\begin{pspicture}(0,0)(6,7)
  \SpecialCoor

  \rput(1,5){\rnode{G}{G}}
  \rput(3,5){\rnode{L}{L}}
  \rput(5,5){\rnode{P}{P}}
       
  \psset{arrows=->,nodesep=3pt,doubleline=true,arrowsize=7pt}
  \ncline{G}{L}       
  \ncline{L}{P}
  \nccurve[angleA=-135,angleB=-45]{P}{G} \naput{$p(x) > 0$}
       
\end{pspicture}

\endTeXtoEPS
\end{document}