removed conditional combinator;
avoid handle _;
showctxt: print_context (cf. local theory context);
searchtheorems: proper find_theorems;
refrain from setting ml_prompts again;
tuned init_pgip;
\index{model checking example|(}%
\index{lfp@{\texttt{lfp}}!applications of|see{CTL}}
\input{CTL/document/Base.tex}
\input{CTL/document/PDL.tex}
\input{CTL/document/CTL.tex}
\index{model checking example|)}