Equivalence of Two Formal Semantics for Functional Logic Programs

A distinctive feature of modern functional logic languages like Toy or Curry is the possibility of programming non-strict and non-deterministic functions with call-time choice semantics. For almost ten years the CRWL framework [6,7] has been the only formal setting covering all these semantic aspects. But recently [1] an alternative proposal has appeared, focusing more on operational aspects. In this work we investigate the relation between both approaches, which is far from being obvious due to the wide gap between both descriptions, even at syntactical level.