\begin{thebibliography}{99}

\bibitem{manna} % OK
Z.\ Manna and R.\ Waldinger,
{\it The Logical Basis for Computer Programming:
Volume 1, Deductive Reasoning},
Addison-Wesley, 1985.

\bibitem{melham} % OK
T.\ F.\ Melham,
{\it The HOL sets library},
University of Cambridge Computer Laboratory,
October 1991.

\bibitem{ind-defs} % OK
T.\ Melham,
`A Package for Inductive Relation Definitions in HOL',
to appear in the Proceedings of the 1991 International Tutorial
and Workshop on the HOL Theorem Proving System, 27--30 August 1991,
Davis California (IEEE Computer Society Press).

\bibitem{description} % OK
University of Cambridge Computer Laboratory,
{\it The HOL System: DESCRIPTION}, revised edition, July 1991.

\end{thebibliography}


