A complete and terminating execution model for constraint handling rules

Hariolf Betz, Frank Raiser, and Thom Frühwirth. A complete and terminating execution model for constraint handling rules. 2010, Ulmer Informatik Berichte 2010-01, Ulm University, Technical Report

We observe that the various formulations of the operational semantics of Constraint Handling Rules proposed over the years fall into a spectrum ranging from the analytical to the pragmatic. While existing analytical formulations facilitate program analysis and formal proofs of program properties, they cannot be implemented as is. We propose a novel operational semantics, which has a strong analytical foundation, while featuring a terminating execution model. We prove its soundness and completeness with respect to existing analytical formulations and we compare its expressivity to that of various other formulations.