a multi engine theorem prover for a description logic of
play

A Multi-Engine Theorem Prover for a Description Logic of Typicality - PowerPoint PPT Presentation

Description Logics Description Logics of typicality Reasoning in ALC + T min Theorem Proving A Multi-Engine Theorem Prover for a Description Logic of Typicality Laura Giordano 1 Valentina Gliozzi 2 Nicola Olivetti 3 Gian Luca Pozzato 2 Luca


  1. Description Logics Description Logics of typicality Reasoning in ALC + T min Theorem Proving A Multi-Engine Theorem Prover for a Description Logic of Typicality Laura Giordano 1 Valentina Gliozzi 2 Nicola Olivetti 3 Gian Luca Pozzato 2 Luca Violanti 4 1 DISIT - Universit´ a Piemonte Orientale - Alessandria, Italy 2 Dipartimento di Informatica, Universit´ a degli Studi di Torino, Italy 3 Aix Marseille Univ. - CNRS, ENSAM, Univ. de Toulon - LSIS UMR 7296, Marseille - France 4 NCR Edinburgh - United Kingdom AI*IA 2015 Luca Violanti A Multi-Engine Theorem Prover for a Description Logic of Typicality

  2. Description Logics Description Logics of typicality Introduction Reasoning in ALC + T min Theorem Proving Description Logics Description Logics Important formalisms of knowledge representation Two key advantages: well-defined semantics based on first-order logic good trade-o ff between expressivity and complexity at the base of languages for the semantic (e.g. OWL) Knowledge bases Two components: TBox=inclusion relations among concepts Platypus v Mammal ABox= instances of concepts and roles = properties and relations among individuals Platypus ( perry ) Luca Violanti A Multi-Engine Theorem Prover for a Description Logic of Typicality

  3. Description Logics Description Logics of typicality Introduction Reasoning in ALC + T min Theorem Proving Description Logics Description Logics Important formalisms of knowledge representation Two key advantages: well-defined semantics based on first-order logic good trade-o ff between expressivity and complexity at the base of languages for the semantic (e.g. OWL) Knowledge bases Two components: TBox=inclusion relations among concepts Platypus v Mammal ABox= instances of concepts and roles = properties and relations among individuals Platypus ( perry ) Luca Violanti A Multi-Engine Theorem Prover for a Description Logic of Typicality

  4. Description Logics Description Logics of typicality Introduction Reasoning in ALC + T min Theorem Proving Description Logics Description Logics Important formalisms of knowledge representation Two key advantages: well-defined semantics based on first-order logic good trade-o ff between expressivity and complexity at the base of languages for the semantic (e.g. OWL) Knowledge bases Two components: TBox=inclusion relations among concepts Platypus v Mammal ABox= instances of concepts and roles = properties and relations among individuals Platypus ( perry ) Luca Violanti A Multi-Engine Theorem Prover for a Description Logic of Typicality

  5. Description Logics Description Logics of typicality Introduction Reasoning in ALC + T min Theorem Proving Description Logics Description Logics Important formalisms of knowledge representation Two key advantages: well-defined semantics based on first-order logic good trade-o ff between expressivity and complexity at the base of languages for the semantic (e.g. OWL) Knowledge bases Two components: TBox=inclusion relations among concepts Platypus v Mammal ABox= instances of concepts and roles = properties and relations among individuals Platypus ( perry ) Luca Violanti A Multi-Engine Theorem Prover for a Description Logic of Typicality

  6. Description Logics Description Logics of typicality Introduction Reasoning in ALC + T min Theorem Proving Description Logics Reasoning TBox = taxonomy of concepts need of representing prototypical properties and of reasoning about defeasible inheritance integration with nonmonotonic reasoning mechanism to handle defeasible inheritance [BH95, BLW06, DLN + 98, DNR02, ELST04, Str93] all these methods present some di ffi culties Our solution DLs + typicality operator T for defeasible reasoning in DLs [GGOP13] meaning of T : (for any concept C ) T ( C ) singles out the “typical” instances of C semantics of T defined by a set of postulates that are a restatement of Kraus-Lehmann-Magidor axioms of preferential logic P Luca Violanti A Multi-Engine Theorem Prover for a Description Logic of Typicality

  7. Description Logics Description Logics of typicality Introduction Reasoning in ALC + T min Theorem Proving Description Logics Reasoning TBox = taxonomy of concepts need of representing prototypical properties and of reasoning about defeasible inheritance integration with nonmonotonic reasoning mechanism to handle defeasible inheritance [BH95, BLW06, DLN + 98, DNR02, ELST04, Str93] all these methods present some di ffi culties Our solution DLs + typicality operator T for defeasible reasoning in DLs [GGOP13] meaning of T : (for any concept C ) T ( C ) singles out the “typical” instances of C semantics of T defined by a set of postulates that are a restatement of Kraus-Lehmann-Magidor axioms of preferential logic P Luca Violanti A Multi-Engine Theorem Prover for a Description Logic of Typicality

  8. Description Logics Description Logics of typicality Introduction Reasoning in ALC + T min Nonmonotonic semantics ALC + T min Theorem Proving The logic ALC + T min Basic notions A KB comprises assertions T ( C ) v D T ( Student ) v FacebookUsers means “normally, students use Facebook” T is nonmonotonic C v D does not imply T ( C ) v T ( D ) Luca Violanti A Multi-Engine Theorem Prover for a Description Logic of Typicality

  9. Description Logics Description Logics of typicality Introduction Reasoning in ALC + T min Nonmonotonic semantics ALC + T min Theorem Proving The logic ALC + T min Basic notions A KB comprises assertions T ( C ) v D T ( Student ) v FacebookUsers means “normally, students use Facebook” T is nonmonotonic C v D does not imply T ( C ) v T ( D ) Luca Violanti A Multi-Engine Theorem Prover for a Description Logic of Typicality

  10. Description Logics Description Logics of typicality Introduction Reasoning in ALC + T min Nonmonotonic semantics ALC + T min Theorem Proving The logic ALC + T min Example T ( BasketballPlayer ) v ¬ Rich T ( BasketballPlayer u NBAMember ) v Rich Reasoning ABox: BasketballPlayer ( marco ) Expected conclusions: ¬ Rich ( marco ) Luca Violanti A Multi-Engine Theorem Prover for a Description Logic of Typicality

  11. Description Logics Description Logics of typicality Introduction Reasoning in ALC + T min Nonmonotonic semantics ALC + T min Theorem Proving The logic ALC + T min Example T ( BasketballPlayer ) v ¬ Rich T ( BasketballPlayer u NBAMember ) v Rich Reasoning ABox: BasketballPlayer ( marco ) Expected conclusions: ¬ Rich ( marco ) Luca Violanti A Multi-Engine Theorem Prover for a Description Logic of Typicality

  12. Description Logics Description Logics of typicality Introduction Reasoning in ALC + T min Nonmonotonic semantics ALC + T min Theorem Proving The logic ALC + T min Example T ( BasketballPlayer ) v ¬ Rich T ( BasketballPlayer u NBAMember ) v Rich Reasoning ABox: BasketballPlayer ( marco ) Expected conclusions: ¬ Rich ( marco ) Luca Violanti A Multi-Engine Theorem Prover for a Description Logic of Typicality

  13. Description Logics Description Logics of typicality Introduction Reasoning in ALC + T min Nonmonotonic semantics ALC + T min Theorem Proving The logic ALC + T min Example T ( BasketballPlayer ) v ¬ Rich T ( BasketballPlayer u NBAMember ) v Rich Reasoning ABox: BasketballPlayer ( marco ) NBAMember ( marco ) Expected conclusions: Rich ( marco ) Luca Violanti A Multi-Engine Theorem Prover for a Description Logic of Typicality

  14. Description Logics Description Logics of typicality Introduction Reasoning in ALC + T min Nonmonotonic semantics ALC + T min Theorem Proving The logic ALC + T min Example T ( BasketballPlayer ) v ¬ Rich T ( BasketballPlayer u NBAMember ) v Rich Reasoning ABox: BasketballPlayer ( marco ) NBAMember ( marco ) Expected conclusions: Rich ( marco ) Luca Violanti A Multi-Engine Theorem Prover for a Description Logic of Typicality

  15. Description Logics Description Logics of typicality Introduction Reasoning in ALC + T min Nonmonotonic semantics ALC + T min Theorem Proving The logic ALC + T min Example T ( BasketballPlayer ) v ¬ Rich T ( BasketballPlayer u NBAMember ) v Rich Reasoning ABox: BasketballPlayer ( marco ) NBAMember ( marco ) Expected conclusions: Rich ( marco ) Luca Violanti A Multi-Engine Theorem Prover for a Description Logic of Typicality

  16. Description Logics Description Logics of typicality Introduction Reasoning in ALC + T min Nonmonotonic semantics ALC + T min Theorem Proving Weakness of monotonic semantics Logic ALC + T The operator T is nonmonotonic, but... The logic is monotonic If KB | = F , then KB’ | = F for all KB’ ◆ KB Example in the KB of the previous slides: if BasketballPlayer ( marco ) 2 ABox, we are not able to: assume that T ( BasketballPlayer )( marco ) infer that ¬ Rich ( marco ) Luca Violanti A Multi-Engine Theorem Prover for a Description Logic of Typicality

  17. Description Logics Description Logics of typicality Introduction Reasoning in ALC + T min Nonmonotonic semantics ALC + T min Theorem Proving Weakness of monotonic semantics Logic ALC + T The operator T is nonmonotonic, but... The logic is monotonic If KB | = F , then KB’ | = F for all KB’ ◆ KB Example in the KB of the previous slides: if BasketballPlayer ( marco ) 2 ABox, we are not able to: assume that T ( BasketballPlayer )( marco ) infer that ¬ Rich ( marco ) Luca Violanti A Multi-Engine Theorem Prover for a Description Logic of Typicality

Download Presentation
Download Policy: The content available on the website is offered to you 'AS IS' for your personal information and use only. It cannot be commercialized, licensed, or distributed on other websites without prior consent from the author. To download a presentation, simply click this link. If you encounter any difficulties during the download process, it's possible that the publisher has removed the file from their server.

Recommend


More recommend