IMP -- A while-language and two semantics
The formalization of the denotational and operational semantics of
a simple while-language together with an equivalence proof between the two
semantics. The whole development essentially formalizes/transcribes chapters
2 and 5 of
@book{Winskel,
author = {Glynn Winskel},
title = {The Formal Semantics of Programming Languages},
publisher = {MIT Press},
year = 1993}.
There is a
report by Lötzbeyer and Sandner.
A much extended version of this development is found in
HOL/IMP.