Stepwise Debugging of Description-Logic Programs

Abstract

Abstract. Description-logic programs (or DL-programs for short) combine logic programs under the answer-set semantics with description logics for semanticweb reasoning. In order for a wider acceptance of the formalism among semanticweb engineers, it is vital to have adequate tools supporting the program development process. In particular, methods for debugging DL-programs are needed. In this paper, we introduce a framework for interactive stepping through a DLprogram as a means for debugging which builds on recent results on stepping for standard answer-set programs. To this end, we provide a computation model for DL-programs using states based on the rules that a user considers as active in the program and the resulting intermediate interpretation. During the course of stepping, the interpretations of the subsequent states evolve towards an answer set of the overall program. Compared to the case of standard answer-set programs, we need more involved notions of states and computations in the presence of DL-atoms. In particular, if non-convex DL-atoms are involved, we have to allow for non-stable computations. Intuitively speaking, we realise this by allowing the user to assume the truth of propositional atoms which must be justified in subsequent states. To keep track of these additional atoms, we extend the well-known notion of an unfounded set for DL-programs.

Stepwise debugging of answer-set programs

“…The framework introduced in this paper subsumes and significantly extends previous versions of the stepping technique for normal logic programs(Oetsch et al 2010b; and DL-programs(Oetsch et al 2012b).…”

“…Due to the fully declarative semantics of ASP, it can be quite tedious to detect an error in an answer-set program. In recent years, debugging in ASP has received some attention (Brain and De Vos 2005;Syrjänen 2006;Brain et al 2007b;Pührer 2007;Gebser et al 2008;Gebser et al 2009;Pontelli et al 2009;Oetsch et al 2010a;Oetsch et al 2010b;Oetsch et al 2012b;Frühstück et al 2013;Polleres et al 2013;Shchekotykhin 2015). These previous works are important contributions towards ASP development support, however current approaches come with limitations to their practical applicability.…”

SeaLion: An eclipse-based IDE for answer-set programming with advanced debugging support

“…Moreover, the use of function symbols in answer-set programs leads to infinite programs obtained by the naïve grounding that was assumed in the previous approach. To overcome these major limitations, we lifted the stepping framework to DL-programs (Oetsch et al 2012), and finally to the languages of Gringo and DLV (Oetsch et al 2013). Hence, we could implement stepping in SeaLion fully covering these two ASP languages.…”