[texhax] can anyone explain this error in pstricks?

[Herbert Voss]

Zbigniew Nitecki wrote:
> The set of commands below, when run on its own (in a test file using
> the correct packages and article style, TeX and Ghostscript in
> TeXShop), runs fine;  when inserted in a (much) larger file (also with
> all the right packages), following a theorem (lemma) environment and
> preceding a proof environment, it returns a set of warnings as follows:
please provide always full working examples ...

\documentclass{minimal}

\usepackage{pst-plot,pst-math,pstricks-add}
\SpecialCoor
\def\func{x COS x  1 add div}

\begin{document}

\begin{pspicture}(-0.5,-2.5)(5.5,2.5)
  \psset{xunit=0.25 cm, yunit=1.5 cm}
  \uput[ur](0.75,0.5){$y=f{x}$}
  \uput[dr](0.75,-0.5){\textcolor{darkgray}{$y=-f{x}$}}
  \pscustom[linewidth=1.2pt,fillstyle=solid, fillcolor=lightgray]{
    \psplot{0}{PI 13 mul 2 div}{\func}
    \psline(! PI 13 mul 2 div 0)(0,0) }
  \psplot[linecolor=darkgray]{0}{22}{x COS x  1 add div neg}
  \psaxes[ticks=none]{<->}(0,0)(-1,-1.2)(22,1.2)
\end{pspicture}

\end{document}


Herbert