%% 
%%  A DANTE-Edition example
%% 
%% 
%%  Copyright (C) 2011 Herbert Voss
%% 
%%  It may be distributed and/or modified under the conditions
%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
%% 
%%  See http://www.latex-project.org/lppl.txt for details.
%% 
%% 
%% ==== 
% Show page(s) 1
%% 
\documentclass[]{article}
\pagestyle{empty}
\setlength\textwidth{201.70511pt}
\setlength\parindent{0pt}

\usepackage{pstricks-add,pst-func}

\begin{document}
\begin{pspicture*}(-3,-3.2)(3.5,3.5)
\psaxes{->}(0,0)(-3,-3)(3.2,3)
\psplotImp[linewidth=2pt,
  linecolor=red](-5,-2.1)(5,2.1){
  x dup mul y dup
  mul add 4 sub }% circle r=2
\uput[45](0,2){$x^2+y^2-4=0$}
\psplotImp[linewidth=2pt,
  linecolor=blue,
  algebraic](-5,-3)(4,2.4)%
  { (x+1)^2+y^2-4 }
\end{pspicture*}
\end{document}