1 \begin{thebibliography}{1}
4 Richard Bird and Philip Wadler.
5 \newblock {\em Introduction to Functional Programming}.
6 \newblock Prentice-Hall, 1988.
10 \newblock {\em The Isabelle Reference Manual}.
11 \newblock University of Cambridge, Computer Laboratory.
12 \newblock \verb$http://www.in.tum.de/~isabelle/dist/$.
14 \bibitem{Isa-Logics-Man}
16 \newblock {\em Isabelle's Object-Logics}.
17 \newblock University of Cambridge, Computer Laboratory.
18 \newblock \verb$http://www.in.tum.de/~isabelle/dist/$.
22 \newblock {\em ML for the Working Programmer}.
23 \newblock Cambridge University Press, 2nd edition, 1996.