Nardi, andR. Rosati. Autoepistemic description logics. In Proc. of IJCAI-97, pages 136--141,1997. 6. O. Etzioni,S. Hanks,D. Weld,D. Draper,N.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....only. In addition, we use two nonmonotonic modal operators: a minimal knowledge operator K and a default assumption operator A. These are interpreted according to the nonmonotonic modal logic MKNF [ Lifschitz,1994 ] and give rise to the so called autoepistemic description logic ALCKNF [ Donini et al. 1997 ] which thus corresponds to a fragment of first order MKNF . Due to space limitations, we only briefly introduce ALCKNF , and refer to [ Donini et al. 1997 ] for a detailed introduction to such a formalism. The logic ALCKNF allows for representing a domain of interest in terms of concepts and ....

....to the nonmonotonic modal logic MKNF [ Lifschitz,1994 ] and give rise to the so called autoepistemic description logic ALCKNF [ Donini et al. 1997 ] which thus corresponds to a fragment of first order MKNF . Due to space limitations, we only briefly introduce ALCKNF , and refer to [ Donini et al. 1997 ] for a detailed introduction to such a formalism. The logic ALCKNF allows for representing a domain of interest in terms of concepts and roles. Concepts model classes of individuals, while roles model relationships between classes. Starting with atomic concepts and atomic roles, which are ....

Francesco M. Donini, Daniele Nardi, and Riccardo Rosati. Autoepistemic description logics. In Proc. of the 15th Int. Joint Conf. on Artificial Intelligence (IJCAI'97), pages 136--141, 1997.

.... defaults can be naturally formalized through MKNF theories with quantifying in (see [15] Moreover, it has been recently proven that some implemented nonmonotonic features of frame based knowledge representation systems can be formally reconstruced in terms of MKNF theories with quantifying in [3]. In particular, it is worth pointing out the relationship between quantifying in in MKNF and (disjunctive) Datalog. Indeed, referring to Definition 20 and to the translation, provided in [16] of extended disjunctive logic programs in terms of MKNF formulas, it is immediate to see that the ....

F. M. Donini, D. Nardi, and R. Rosati. Autoepistemic description logics. In Proc. of the 15th Int. Joint Conf. on Artificial Intelligence (IJCAI'97), pages 136--141, 1997.

....formulae on single states, while traversing the graph. 2 Logical formalism The technical background of our proposal is constituted by a logical formalism L that originates from a suitable integration of modal mu calculus and autoepistemic de scription logics (see respectively [ 24; 9 ] and [ 8 ] for an introduction to these formalisms) The basic elements of L are a finite set of actions Act , a countable set of propositions Prop, and a countable set of propositional variables Var . Formulae of the formalism are divided in two layers: ffl state description formulae: p : A j p 1 p 2 ....

....from A. An interpretation W is a model for Sigma iff W is a maximal set of interpretations satisfying Sigma, i.e. for each interpretation W 0 , if W ae W 0 then W 0 does not satisfy Sigma. This corresponds to impose a minimal knowledge semantics on the epistemic states of the agent [ 8 ] In fact, each interpretation can be viewed as a Kripke structure in which each pre interpretation is a possible world, and each world is connected to all worlds in the structure: only structures satisfying Sigma and having a maximal set of possible worlds are considered, which maximizes ....

F. M. Donini, D. Nardi, and R. Rosati. Autoepistemic description logics. In Proc. of IJCAI'97, pages 136--141, 1997.

....PDL with atomic programs only. In addition, we use two nonmonotonic modal operators: a minimal knowledge operator K and a default assumption operator A. These are interpreted according to the nonmonotonic modal logic MKNF [11] and give rise to the so called Autoepistemic Description Logic ALCKNF [5]. We do not have the space here to formally introduce such a logical framework, we refer the reader to [3] and [5] Rather, we give an intuition of the underlying semantics. The interpretation structures of DLs (PDLs) are essentially graphs labeled both on nodes and arcs. Nodes, called ....

....K and a default assumption operator A. These are interpreted according to the nonmonotonic modal logic MKNF [11] and give rise to the so called Autoepistemic Description Logic ALCKNF [5] We do not have the space here to formally introduce such a logical framework, we refer the reader to [3] and [5]. Rather, we give an intuition of the underlying semantics. The interpretation structures of DLs (PDLs) are essentially graphs labeled both on nodes and arcs. Nodes, called individuals in DLs, states in PDLs) are labeled by concepts (formulae in PDLs) that denote properties of individuals. ....

Francesco M. Donini, Daniele Nardi, and Riccardo Rosati. Autoepistemic description logics. In Proceedings of the Fifteenth International Joint Conference on Artificial Intelligence (IJCAI-97), pages 136--141, 1997.

No context found.

F. M. Donini, D. Nardi, and R. Rosati, 1997b. Autoepistemic description logics. To appear in Proc. of IJCAI-97.

No context found.

F. M. Donini, D. Nardi, and R. Rosati, 1997b. Autoepistemic description logics. To appear in Proc. of IJCAI-97.

....and the corresponding PDL. In addition, we use the two nonmonotonic modal operators: a minimal knowledge operator K and a default assumption operator A. These are interpreted according to the nonmonotonic modal logic MKNF [12] and give rise to the so called autoepistemic description logic ALCKNF [5]. We do not have the space here to formally introduce such a logical framework, we refer the reader to [3] and [5] Rather, we give an intuition of the underlying semantics. The interpretation structures of DLs (PDLs) are essentially graphs labeled both on nodes and arcs. Nodes, called individuals ....

....K and a default assumption operator A. These are interpreted according to the nonmonotonic modal logic MKNF [12] and give rise to the so called autoepistemic description logic ALCKNF [5] We do not have the space here to formally introduce such a logical framework, we refer the reader to [3] and [5]. Rather, we give an intuition of the underlying semantics. The interpretation structures of DLs (PDLs) are essentially graphs labeled both on nodes and arcs. Nodes, called individuals in DLs, states in PDLs) are labeled by concepts (formulae in PDLs) that denote properties of individuals. ....

F. M. Donini, D. Nardi, and R. Rosati. Autoepistemic description logics. In Proc. of IJCAI-97, pages 136--141, 1997.

....to a concept to those of other concepts. One can establish a hierarchy of concepts, based on set containment (called subsumption) We focus on a well known DL, ALC, 45] and its epistemic extension, ALCK, obtained by adding a modal operator interpreted in terms of minimal knowledge as in [17, 18, 20]. Such an extension plays a critical role in our formalization of dynamic systems. The abstract syntax of ALC is defined as follows: C; D : A j j j C u D j C t D j :C j 9R.C j 8R.C where A denotes an atomic concept, C and D denote generic concepts, R denotes an atomic role. We shall give ....

....according to the kind of obstacle encountered. Second, the notion of epistemic state of the agent can be exploited, since it can be used to address several issues arising in complex dynamic domains. In particular, we are currently focusing on the following aspects: 1. Frame problem. It turns out [20] that a slight extension of ALCK allows for the representation of default rules, thus allowing for the formalization of the notion of default persistence of knowledge, realized through the use of such rules. This property, together with the notion of default persistence of ignorance encoded in the ....

F. M. Donini, D. Nardi, and R. Rosati. Autoepistemic description logics. In Proceedings of the Fifteenth International Joint Conference on Artificial Intelligence (IJCAI-97), pages 136--141, 1997.

No context found.

Nardi, andR. Rosati. Autoepistemic description logics. In Proc. of IJCAI-97, pages 136--141,1997. 6. O. Etzioni,S. Hanks,D. Weld,D. Draper,N.

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