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Efficient paraconsistent reasoning with ontologies and rules
- Procs. of IJCAI. IJCAI/AAAI (2015
"... Description Logic (DL) based ontologies and non-monotonic rules provide complementary features whose combination is crucial in many applications. In hybrid knowledge bases (KBs), which combine both formalisms, for large real-world applications, often integrating knowledge originating from dif-ferent ..."
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Cited by 6 (6 self)
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Description Logic (DL) based ontologies and non-monotonic rules provide complementary features whose combination is crucial in many applications. In hybrid knowledge bases (KBs), which combine both formalisms, for large real-world applications, often integrating knowledge originating from dif-ferent sources, inconsistencies can easily occur. These commonly trivialize standard reasoning and prevent us from drawing any meaningful conclu-sions. When restoring consistency by changing the KB is not possible, paraconsistent reasoning offers an alternative by allowing us to obtain meaningful conclusions from its consistent part. In this paper, we address the problem of efficiently obtaining meaningful conclusions from (possibly inconsistent) hybrid KBs. To this end, we de-fine two paraconsistent semantics for hybrid KBs which, beyond their differentiating properties, are faithful to well-known paraconsistent semantics as well as the non-paraconsistent logic they extend, and tractable if reasoning in the DL component is. 1
Three-valued paraconsistent reasoning for Semantic Web agents
- Proceedings of KES-AMSTA 2010, Part I, volume 6070 of LNAI
, 2010
"... Abstract. Description logics [1] refer to a family of formalisms concentrated around concepts, roles and individuals. They are used in many multiagent and semantic web applications as a foundation for specifying knowledge bases and reasoning about them. One of widely applied description logics is SH ..."
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Abstract. Description logics [1] refer to a family of formalisms concentrated around concepts, roles and individuals. They are used in many multiagent and semantic web applications as a foundation for specifying knowledge bases and reasoning about them. One of widely applied description logics is SHIQ [7,8]. In the current paper we address the problem of inconsistent knowledge. Inconsistencies may naturally appear in the considered application domains, for example as a result of fusing knowledge from distributed sources. We define three threevalued paraconsistent semantics for SHIQ, reflecting different meanings of concept inclusion of practical importance. We also provide a quite general syntactic condition of safeness guaranteeing satisfiability of a knowledge base w.r.t. threevalued semantics and define a faithful translation of our formalism into a suitable version of a two-valued description logic. Such a translation allows one to use existing tools and SHIQ reasoners to deal with inconsistent knowledge. 1
Inconsistency-tolerant reasoning with OWL DL
- Int. J. Approx. Reasoning
, 2014
"... Abstract The Web Ontology Language (OWL) is a family of description logic based ontology languages for the Semantic Web and gives well defined meaning to web accessible information and services. The study of inconsistency-tolerant reasoning with description logic knowledge bases is especially impor ..."
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Abstract The Web Ontology Language (OWL) is a family of description logic based ontology languages for the Semantic Web and gives well defined meaning to web accessible information and services. The study of inconsistency-tolerant reasoning with description logic knowledge bases is especially important for the Semantic Web since knowledge is not always perfect within it. An important challenge is strengthening the inference power of inconsistency-tolerant reasoning because it is normally impossible for paraconsistent logics to obey all important properties of inference together. This paper presents a non-classical DL called quasi-classical description logic (QCDL) to tolerate inconsistency in OWL DL which is a most important sublanguage of OWL supporting those users who want the maximum expressiveness while retaining computational completeness (i.e., all conclusions are guaranteed to be computable) and decidability (i.e., all computations terminate in finite time). Instead of blocking those inference rules, we validate them conditionally and partially, under which more useful information can still be inferred when inconsistency occurs. This new non-classical DL possesses several important properties as well as its paraconsistency in DL, but it does not bring any extra complexity in worst case. Finally, a transformationbased algorithm is proposed to reduce reasoning problems in QCDL to those in DL so that existing OWL DL reasoners can be used to implement inconsistencytolerant reasoning. Based on this algorithm, a prototype OWL DL paraconsistent reasoner called PROSE is implemented. Preliminary experiments show that PROSE produces more intuitive results for inconsistent knowledge bases than other systems in general.
Reasoning Efficiently with Ontologies and Rules in the Presence of Inconsistencies (Extended Abstract)
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Reasoning with Inconsistencies in Hybrid MKNF Knowledge Bases
, 2012
"... This paper is concerned with the handling of inconsistencies occurring in the combination of description logics and rules, especially in hybrid MKNF knowledge bases. More precisely, we present a paraconsistent semantics for hybrid MKNF knowledge bases (called para-MKNF knowledge bases) based on four ..."
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This paper is concerned with the handling of inconsistencies occurring in the combination of description logics and rules, especially in hybrid MKNF knowledge bases. More precisely, we present a paraconsistent semantics for hybrid MKNF knowledge bases (called para-MKNF knowledge bases) based on four-valued logic as proposed by Belnap. We also reduce this paracon-sistent semantics to the stable model semantics via a linear transformation operator, which shows the relationship between the two semantics and in-dicates that the data complexity in our paradigm is not higher than that of classical reasoning. Moreover, we provide fixpoint operators to compute paraconsistent MKNF models, each suitable to different kinds of rules. At last we present the data complexity of instance checking in different para-MKNF knowledge bases.
Noname manuscript No. (will be inserted by the editor) Wiener’s Lemma for Singular Integral Operators of Bessel Potential Type
, 2013
"... Abstract In this paper, we introduce an algebra of singular integral operators containing Bessel potentials of positive order, and show that the corresponding unital Banach algebra is an inverseclosed Banach subalgebra of B(L q w), the Banach algebra of all bounded operators on the weighted space L ..."
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Abstract In this paper, we introduce an algebra of singular integral operators containing Bessel potentials of positive order, and show that the corresponding unital Banach algebra is an inverseclosed Banach subalgebra of B(L q w), the Banach algebra of all bounded operators on the weighted space L q w, for all 1 ≤ q < ∞ and Muckenhoupt Aq-weights w.
PROSE: A Plugin-based Paraconsistent OWL
"... Abstract. The study of paraconsistent reasoning with ontologies is es-pecially important for the Semantic Web since knowledge is not always perfect within it. Quasi-classical semantics is proven to rationally draw more meaningful conclusions even from an inconsistent ontology with the stronger infer ..."
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Abstract. The study of paraconsistent reasoning with ontologies is es-pecially important for the Semantic Web since knowledge is not always perfect within it. Quasi-classical semantics is proven to rationally draw more meaningful conclusions even from an inconsistent ontology with the stronger inference power of paraconsistent reasoning. In our previ-ous work, we have conceived a quasi-classical framework called prose to provide rich paraconsistent reasoning services for OWL ontologies, whose architecture contains three parts: a classical OWL reasoner, a quasi-classical transformer, and OWL API connecting with them. This paper finally implements prose where quasi-classical transformer is bulit as a plugin for paraconsistent reasoning on classical reasoners. Additionally, we select three popular classical OWL reasoners (i.e., Pellet, HermiT, and FaCT++) and two typical kinds of reasoning services (i.e., QC-consistency checking and QC-classification) for users. As we excepted, prose does exactly enable current classical OWL reasoners to tolerate inconsistency in a simple and convenient way. Furthermore, we evaluate the three reasoners in three dimensions (class, property, individual) and, as a result, those results can amend the analysis of the three reasoners on inconsistent ontologies. 1
Well-founded Paraconsistent Semantics for Hybrid Theories composed of Rules and Ontologies
"... Description Logic (DL) based ontologies and non-monotonic rules provide complementary features whose combination is crucial in many applications. In hybrid knowledge bases (KBs), which combine both formalisms, for large real-world applications, often integrating knowledge originating from dif-ferent ..."
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Description Logic (DL) based ontologies and non-monotonic rules provide complementary features whose combination is crucial in many applications. In hybrid knowledge bases (KBs), which combine both formalisms, for large real-world applications, often integrating knowledge originating from dif-ferent sources, inconsistencies can easily occur. These commonly trivialize standard reasoning and prevent us from drawing any meaningful conclu-sions. When restoring consistency by changing the KB is not possible, paraconsistent reasoning offers an alternative by allowing us to obtain meaningful conclusions from its consistent part. In this paper, we address the problem of efficiently obtaining meaningful conclusions from (possibly inconsistent) hybrid KBs. To this end, we de-fine two paraconsistent semantics for hybrid KBs which, beyond their differentiating properties, are faithful to well-known paraconsistent semantics as well as the non-paraconsistent logic they extend, and tractable if reasoning in the DL component is.
A Tableau Algorithm for Paraconsistent and Nonmonotonic Reasoning in Description Logic-Based System
"... Abstract. This paper proposes a paraconsistent and nonmonotonic extension of description logic by planting a nonmonotonic mechanism called minimal in-consistency in paradoxical description logics, which is a paraconsistent version of description logics. A precedence relation between two paradoxical ..."
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Abstract. This paper proposes a paraconsistent and nonmonotonic extension of description logic by planting a nonmonotonic mechanism called minimal in-consistency in paradoxical description logics, which is a paraconsistent version of description logics. A precedence relation between two paradoxical models of knowledge bases is firstly introduced to obtain minimally paradoxical mod-els by filtering those models which contain more inconsistencies than others. A new entailment relationship between a KB and an axiom characterized by minimal paradoxical models is applied to characterize the semantics of a para-consistent and nonmonotonic description logic. An important advantage of our adaptation is simultaneously overtaking proverbial shortcomings of existing two kinds extensions of description logics: the weak inference power of paraconsis-tent description logics and the incapacity of nonmonotonic description logics in handling inconsistencies. Moreover, our paraconsistent and nonmonotonic exten-sion not only preserves the syntax of description logic but also maintains the de-cidability of basic reasoning problems in description logics. Finally, we develop a sound and complete tableau algorithm for instance checking with the minimally paradoxical semantics. 1