We propose a combination of logic programming under the answer set semantics with thedescription logics SHIF(D) and SHOIN(D), which underly the Web ontology languagesOWL Lite and OWL DL, respectively. To this end, we introduce description logic programs (ordl-programs), which consist of a description logic knowledge base L and a finite set P ofdescription logic rules (or dl-rules). Such rules are similar to usual rules in nonmonotoniclogic programs, but they may also contain queries to L, possibly under default negation, intheir bodies. They allow for building rules on top of ontologies but also, to a limited extent,building ontologies on top of rules. We define a suite of semantics for various classes ofdl-programs, which conservatively extend the standard semantics of the respective classesand coincide with it in absence of a description logic knowledge base. More concretely,we generalize positive, stratified, and arbitrary normal logic programs to dl-programs, anddefine a Herbrand model semantics for them. We show that they have similar properties asordinary logic programs, and also provide fixpoint characterizations in terms of (iterated)consequence operators. For arbitrary dl-programs, we define answer sets by generalizingGelfond and Lifschitz’s notion of a transform, leading to a strong and a weak answer setsemantics, which are based on reductions to the semantics of positive dl-programs andordinary positive logic programs, respectively. We also show how the weak answer setscan be computed utilizing answer sets of ordinary normal logic programs. Furthermore, weshow how some advanced reasoning tasks for the Semantic Web, including different formsof closed-world reasoning and default reasoning, as well as DL-safe rules, can be realizedon top of dl-programs. Finally, we give a precise picture of the computational complexityof dl-programs, and we describe efficient algorithms and a prototype implementation ofdl-programs which is available on the Web.
Combining Answer Set Programming with Description Logics for the Semantic Web -- [Winner of the ARTIFICIAL INTELLIGENCE PROMINENT PAPER AWARD 2013]
IANNI, Giovambattista;
2008-01-01
Abstract
We propose a combination of logic programming under the answer set semantics with thedescription logics SHIF(D) and SHOIN(D), which underly the Web ontology languagesOWL Lite and OWL DL, respectively. To this end, we introduce description logic programs (ordl-programs), which consist of a description logic knowledge base L and a finite set P ofdescription logic rules (or dl-rules). Such rules are similar to usual rules in nonmonotoniclogic programs, but they may also contain queries to L, possibly under default negation, intheir bodies. They allow for building rules on top of ontologies but also, to a limited extent,building ontologies on top of rules. We define a suite of semantics for various classes ofdl-programs, which conservatively extend the standard semantics of the respective classesand coincide with it in absence of a description logic knowledge base. More concretely,we generalize positive, stratified, and arbitrary normal logic programs to dl-programs, anddefine a Herbrand model semantics for them. We show that they have similar properties asordinary logic programs, and also provide fixpoint characterizations in terms of (iterated)consequence operators. For arbitrary dl-programs, we define answer sets by generalizingGelfond and Lifschitz’s notion of a transform, leading to a strong and a weak answer setsemantics, which are based on reductions to the semantics of positive dl-programs andordinary positive logic programs, respectively. We also show how the weak answer setscan be computed utilizing answer sets of ordinary normal logic programs. Furthermore, weshow how some advanced reasoning tasks for the Semantic Web, including different formsof closed-world reasoning and default reasoning, as well as DL-safe rules, can be realizedon top of dl-programs. Finally, we give a precise picture of the computational complexityof dl-programs, and we describe efficient algorithms and a prototype implementation ofdl-programs which is available on the Web.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
