This paper focuses on the expressive power of disjunctive and normal logic programs under the stable model semantics over finite, infinite, or arbitrary structures. A translation from disjunctive logic programs into normal logic programs is proposed and then proved to be sound over infinite structures. The equivalence of expressive power of two kinds of logic programs over arbitrary structures ...

This article reflects our experience with the preservation of computer programs that once served a scientific purpose, but were not maintained since then. After producing results, published in scientific journals in the 70’s, 80’s and begin 90’s, they were stored provisionally on some kind of persistent medium and are at present restored to current state of the art hardware. We constructed an a...

Software maintainers are often challenged with source code changes to improve software systems, or eliminate defects, in unfamiliar programs. To undertake these tasks a sufficient understanding of the system, or at least a small part of it, is required. One of the most time consuming tasks of this process is locating which parts of the code are responsible for some key functionality or feature....