added an intro lemma for freshness of products; set up
the simplifier so that it can deal with the compact and
long notation for freshness constraints (FIXME: it should
also be able to deal with the special case of freshness
of atoms)
%%
%%
%%
%% smart url or hyperref setup
%%
\newif\ifpdfoutput
\ifx\pdfoutput\undefined
\else
\ifx\pdfoutput\relax
\else
\ifcase\pdfoutput
\else\pdfoutputtrue\fi
\fi
\fi
\ifpdfoutput
\message{PDF output}
\usepackage{color}\definecolor{darkblue}{rgb}{0,0,0.5}
\usepackage[pdftex,a4paper,colorlinks=true,linkcolor=darkblue,citecolor=darkblue,filecolor=darkblue,pagecolor=darkblue,urlcolor=darkblue]{hyperref}
\IfFileExists{thumbpdf.sty}{\usepackage{thumbpdf}}{}
\else
\message{No PDF output}
\usepackage{url}
\fi