[ui] KR Seminar Piatok 13. 5. 10:00 (Igor Sedlar)

Mili kolegovia, uz tento piatok privitame na seminari nasej pracovnej skupiny Igora Sedlara z Ustavu Informatiky Prazskej SAV (predtym FF UK) s prednaskou: Propositional dynamic logic with Belnapian truth values Piatok 13. 5. 10:00 v I-9 Abstrakt: In this talk I discuss a four-valued version of the propositional dy- namic logic PDL, a well-known logical formalism for reasoning about proper- ties of programs [4,5]. The four-valued version, BPDL, results from combining PDL with with the basic four-valued modal logic BK introduced by Odintsov and Wansing [6]. The basic feature of BPDL is that it builds on a generalised ‘Belnapian’ notion of computer state, one that allows formulas to be both true and false or neither true nor false in addition to being true or false simpliciter [1,2,3]. The motivations for studying BPDL are twofold. Firstly, a version of PDL using the generalised notion of state formalises reasoning about programs that modify (possibly incomplete and inconsistent) database-like structures. Such structures abound and a logical formalisation of reasoning about their al- gorithmic transformations could be of vital importance to AI and related areas. Secondly, in addition to practical applications, theoretical questions pertain- ing to the properties of such generalised versions of PDL are interesting in their own right. We illustrate the first point by using BPDL to express state- ments about specific default inference rules. The second point is illustrated by discussing the main technical results concerning BPDL established so far, namely, a decidability result and a weak completeness theorem. Radi vas vsetkych privitame! S pozdravom, -- Martin Homola Homepage: http://ii.fmph.uniba.sk/~homola/ PGP public key: http://ii.fmph.uniba.sk/~homola/publickey.asc