Abstract
This paper introduces an original 2-valued semantics for Normal Logic Programs (NLP), which conservatively extends the Stable Model semantics (SM) to all normal programs. The distinction consists in the revision of one feature of SM, namely its treatment of odd loops, and of infinitely long support chains, over default negation. This single revised aspect, addressed by means of a Reductio ad Absurdum approach, affords a number of fruitful consequences, namely regarding existence, relevance and top-down querying, cumulativity, and implementation. The paper motivates and defines the Revised Stable Models semantics (rSM), justifying and exemplifying it. Properties of rSM are given and contrasted with those of SM. Furthermore, these results apply to SM whenever odd loops and infinitely long chains over negation are absent, thereby establishing significant, not previously known, properties of SM. Conclusions, further work, terminate the paper.

URL:
http://rewerse.net/publications/rewerse-publications.html#REWERSE-RP-2005-101

BibTeX:

@inproceedings{REWERSE-RP-2005-101,
	author = {Luís Moniz Pereira and Alexandre Miguel Pinto},
	title = {Revised Stable Models - a Semantics for Logic Programs},
	booktitle = {Proceedings of 12th Portuguese Conference on Artificial Intelligence, Covilhã, Portugal (5th--8th December 2005)},
	year = {2005},
	volume = {3808},
	series = {LNAI},
	pages = {29--42},
	url = {http://rewerse.net/publications/rewerse-publications.html#REWERSE-RP-2005-101}
}