Now Datatype.occs_in_prems prints the necessary warning ITSELF.
It is also easier to invoke and even works if the induction variable
is a parameter (rather than a free variable).
(* Title: HOLCF/Discrete.thy
ID: $Id$
Author: Tobias Nipkow
Copyright 1997 TUM
Discrete CPOs
*)
Discrete = Discrete1 +
instance discr :: (term)cpo (discr_cpo)
constdefs
undiscr :: ('a::term)discr => 'a
"undiscr x == (case x of Discr y => y)"
end