Persistent constraints in constraint handling rules

Hariolf Betz, Frank Raiser, and Thom Frühwirth. Persistent constraints in constraint handling rules. 2010, 23rd Workshop on (Constraint) Logic Programming, Workshop

Abstract:

In the most abstract de nition of its operational semantics, the declarative and concurrent programming language CHR is trivially non-terminating for a signi cant class of programs. Common re finements of this de nition, in closing the gap to real-world implementations, compromise on declarativity and/or concurrency. Building on recent work and the notion of persistent constraints, we introduce an operational semantics avoiding trivial non-termination without compromising on its essential features.