\newpage
\section*{The Proof Engine}

\ocwsection \label{proofs}
This chapter describes the \Coq\ proof engine, which is also called
the ``refiner'', since it provides a way to build terms by successive
refining steps. Those steps are either primitive rules or higher-level
tactics.
The modules of the proof engine are organized as follows.

\bigskip
\begin{center}\epsfig{file=proofs.dep.ps,width=\linewidth}\end{center}