IMP is a monadic style implementation of the semantics of the (very simple)
language IMP, "plain" the implementation with explicit passing of state.
The semantics of the IMP-language is presented in the book:
"The Formal Semantics of Programming Languages" by Glynn Winskel
(1993, The MIT Press).
For more details on monads, see Philip Wadler's page on:
Author: Markus Mottl <firstname.lastname@example.org>
I'll take it.
New port added. Thanks!