Strong Equivalence of Logic Programs with Counting

Abstract

In answer set programming, two groups of rules are considered strongly equivalent if they have the same meaning in any context. In some cases, strong equivalence of programs in the input language of the grounder gringo can be established by deriving rules of each program from rules of the other. The possibility of such proofs has been demonstrated for a subset of that language that includes comparisons, arithmetic operations, and simple choice rules, but not aggregates. This method is extended here to a class of programs in which some uses of the #count aggregate are allowed.

External Behavior of a Logic Program and Verification of Refactoring

“…The proof assistant anthem-p2p can be used for verifying the correctness of refactoring an ASP program, and also for comparing alternative solutions to the same programming problem (for instance, in classroom teaching and in ASP programming contests). To make this tool more versatile, we plan to make it applicable to programs with aggregates, along the lines of recent publications (Fandinno et al 2022;Lifschitz 2022).…”

Locally Tight Programs

“…Future work will include extending the anthem-p2p algorithm and Theorem 3 to ASP programs that involve aggregate expressions, using the ideas of Fandinno et al (2022) and Lifschitz (2022).…”