more integrity checks of theory names vs. full node names -- at least for the scope of a single use_thys (or "theories" section in ROOT);
\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|)}