[pstricks] looks like a problem

[Cyrille Piatecki]

Dear all,

I want to draw a Kolm triangle --- in economics it's an equilateral 
triangle which is the set where all allocations can be generated if 
there is a public good. As shown in the
code I plot a fonction in cartesian coordinate and I apply \pstilt. But 
it seems that some part of the function which where initialy in the 
positive plan came in the negative one.

I must have make a mistake but I dont know which.

Thank for the help

Cordialy

Cyrille Piatecki

PS Here is the code

%&latex
\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[francais]{babel}
\usepackage{latexsym}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage{pstricks,pst-node,pst-slpe,pst-blur,cmykcolors,pst-solides3d,pst-bar,pst-func}
\usepackage{pst-2dplot,pst-transform,pst-fun,pst-text}
\usepackage{pst-plot,pst-tools,pst-eucl}
\usepackage{pstricks-add}
\begin{document}
%\begin{figure}
\begin{center}
\begin{pspicture}(3,0)(14,6)
\psgrid
\def\gr{
\psline[linecolor=red](4,5)(4,1)(8,1)
\psset{origin={4,1}}
\psplot[algebraic,linewidth=2pt,linecolor=blue]{.5}{4}{x^(-2)}
}
\pspolygon[linecolor=green](4,1)(6,4.425)(8,1)
\gr
\psset{origin={0,0}}
\psarc(4,1){4cm}{0}{90}
\psarc(8,1){4cm}{90}{180}
\psset{origin={-.6,0.2}}%<-
\rput(5,0){\pstilt{60}{\gr}}
\end{pspicture}
\end{center}
\end{document}