Practical Aspects of Declarative Languages: 21th International Symposium, PADL 2019, Lisbon, Portugal, January 14-15, 2019, Proceedings

Answer set programming is a prominent declarative programming paradigm used in formulating combinatorial search problems and implementing distinct knowledge representation formalisms. It is common that several related and yet substantially different answer set programs exist for a given problem. Sometimes these encodings may display significantly different performance. Uncovering precise formal links between these programs is often important and yet far from trivial. This paper claims the correctness of a number of interesting program rewritings. Notably, they assume programs with variables and such important language features as choice, disjunction, and aggregates.