Replaced all but one occurrence of perm_simp_tac by perm_simproc_app,
since perm_simp_tac now behaves in a different way (due to changes
in swap_simps).
\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|)}