A General Framework for Hindley/Milner Type Systems with Constraints

	     Martin Sulzmann, Martin Odersky, Martin Wehr

 Proc. 4th Int. Workshop on Foundations of Object-Oriented Languages

In this paper we present a general framework HM(X) for
Hindley/Milner style type systems with constraints, analogous
to the CLP(X) framework in constrained logic programming.
We show that the type system is sound with respect to a
standard untyped compositional semantics.
We present sufficient conditions on the constraint domain X
so that the principal types property carries over to HM(X).
The conditions turn out to be fairly simple and natural.