Cse@buffalo S.C. Shapiro An Introduction to SNePS 3 Stuart C. Shapiro Department of Computer Science and Engineering and Center for Cognitive Science State.

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S.C. Shapiro

An Introduction to SNePS 3

Stuart C. Shapiro

Department of Computer Science and Engineering

and Center for Cognitive Science

State University of New York at Buffalo

[email protected]

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Outline

• Setting

• Basic SNePS Principles

• Examples

• 4 Kinds of Inference

• Summary

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Parentage of SNePS 3

• SNePS 2.5

• ANALOG– Structured (Conceptually Complete) Variables

• Currently being implemented– in CLOS and/or Java.

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SNePS KRR Style

• Network-based

• Logic-based

• Intended as the LOT of a NL-competent cognitive agent.

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Outline

• Setting

• Basic SNePS Principles

• Examples

• 4 Kinds of Inference

• Summary

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Basic SNePS PrinciplesA Summary of Syntax and Semantics

• Propositional Semantic Network

• Term Logic

• Intensional Representation

• Uniqueness Principle

• Paraconsistent Logic.

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Propositional Semantic Network

• The only well-formed SNePS expressions are nodes.– Arcs do not have semantics

• Do not have assertional import

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Term Logic

• Every well-formed SNePS expression is a term.– Even propositions are denoted by terms.– Propositions can be arguments without leaving first-

order logic.

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Intensional Representation

• SNePS terms represent (denote) intensional (mental) entities.– Cognitively distinct entities denoted by distinct terms

• Even if co-extensional

– Every term denotes a mental entity.• No term for purely technical reasons

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Uniqueness Principle

• No two SNePS terms denote the same entity.– Syntactically distinct terms are semantically distinct.– Full structure sharing.

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Paraconsistent Logic

• A contradiction does not imply anything whatsoever.– A contradiction in one subdomain does not

corrupt another.

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Outline

• Setting

• Basic SNePS Principles

• Examples

• 4 Kinds of Inference

• Summary

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Example: Term Logic& Conceptual Relations

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Example SNePS Ontology

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Example SNePS Ontology

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Example SNePS Ontology

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Example SNePS Ontology

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Example SNePS Ontology

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Example SNePS Ontology

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Cassie talks to Stu

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Outline

• Setting

• Basic SNePS Principles

• Examples

• 4 Kinds of Inference

• Summary

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Wire-Based Inference

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Wire-Based Inference

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Path-Based Inference

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Path-Based Inference

member

class

class

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Path-Based Inference

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Node-Based Inference

If B1 is a talking robot,then B1 is intelligent.

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Node-Based Inference

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Node-Based Inference

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Node-Based Inference

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SNePS 2.5 Generic Version

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Subsumption Inference

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Outline

• Setting

• Basic SNePS Principles

• Examples

• 4 Kinds of Inference

• Summary

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Summary

• SNePS: a Logic- and Network-Based KRR• with its own Syntax, Semantics, Proof Theory• SNePS 3 has 4 kinds of inference

– Wire-based– Path-based– Node-based– Subsumption

• SNePS 3 is currently being implemented.

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SNeRG Home Page

http://www.cse.buffalo.edu/sneps/

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Wire-Based Inference

• Assume

(define-relation

:name “member”

:type entity

:adjust reduce

:limit 1)

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Path-Based Inference

• Assume

(define-path

class

(compose class

(kstar (compose

subclass- !

superclass)))

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Node-Based Inference

E.g. Using and-entailment

{P1, …, Pn} &=> {Q1, …, Qm}