This paper introduces the sequential composition of answer set programs. On the semantic side, we show that the immediate consequence operator of a program can be represented via composition, which allows us to compute the least model semantics of Horn programs without any explicit reference to operators. As a result, we can characterize answer sets algebraically, which provides an algebraic characterization of strong and uniform equivalence. In a broader sense, this paper is a first step towards an algebra of answer set programs and in the future we plan to lift the methods of this paper to wider classes of programs, most importantly to higher-order and disjunctive programs and extensions thereof.

翻译：本文介绍了回答集程序的顺序合成。在语义层面，我们证明了程序的直接后果算子可以通过合成来表示，从而无需显式引用算子即可计算霍恩程序的最小模型语义。由此，我们可以用代数方式刻画回答集，为强等价和均匀等价提供了代数表征。从更广泛的意义上说，本文是迈向回答集程序代数的第一步，未来我们计划将本文的方法推广到更广泛的程序类别，尤其是高阶程序、析取程序及其扩展。