added lemmas antisym_relation_of[simp], asym_relation_of[simp], sym_relation_of[simp], trans_relation_of[simp]
\index{model checking example|(}%
\index{lfp@{\texttt{lfp}}!applications of|see{CTL}}
\input{Base.tex}
\input{PDL.tex}
\input{CTL.tex}
\index{model checking example|)}