Ground Nonmonotonic Modal Logic S5: New Results

Autor: José R. Arrazola Ramírez, Mauricio Osorio Galindo, Verónica Borja Macías, Juan Antonio Navarro Pérez
Rok vydání: 2005
Předmět:
Zdroj: Journal of Logic and Computation. 15:787-813
ISSN: 1465-363X
0955-792X
DOI: 10.1093/logcom/exi042
Popis: We study logic programs under Gelfond's translation in the context of modal logic S5. We show that for arbitrary logic programs (propositional theories where logic negation is associated with default negation) ground nonmonotonic modal logics between T and S5 are equivalent. Furthermore, we also show that these logics are equivalent to a nonmonotonic logic that we construct using the well known F O U R bilattice. We will call this semantic GNM-S5 as a reminder of its origin in the logic S5. Finally we show that, for normal programs, our approach is closely related to theWell-Founded-by-Cases Semantics introduced by Schlipf and the WFS+ proposed by Dix. We prove that GNM-S5 has the properties of classicality and extended cut. While WFS+ also supports classicality it fails to satisfy the extended cut principle, an important property available in other semantics such as stable models. Hence, we claim that GNM-S5 is a good candidate for defining a nonmonotonic semantics closer to the direction of classical logic.
Databáze: OpenAIRE