General Knowledge

Ontological background for everything

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Ontology of everyday knowledge

Mental events need to include representations of KB’s of

other agents to reason about their plans and actions Wants (AgentSmith, Dead(Neo))

need to ‘contain’ inconsistent knowledge to avoid interaction Believes(Gambler1, Faster(HorseA,HorseB)) Believes(Gambler2, ~Faster(HorseA,HorseB))

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Ontology of everyday knowledge

Mental events PROBLEM:

Wants (AgentSmith, Dead(Neo)) Is Dead(Neo) a predicate or a term?

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Ontology of everyday knowledge

Mental events

KB

assumed KB of AgentX as

objects

“Rich(Paul)”

~Rich(Paul)

Believes(AgentX,“Rich(Paul)”)

to reason about what AgentX believes,run AgentX’s ‘interpreter’ with postulated reasoning powers

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Ontology of everyday knowledge

Time non-monotonic change in KB Frame problem – inferring what changes

and what does not Actions as objects Reasoning about events, intervals

fluent calculus

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Ontology of everyday knowledge

Default reasoning (missing information)(more on defaults later)

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Models of general knowledge

1. SUMO (Suggested Upper Merged Ontology)

Alan Pease, IEEE standard Minimal – basis for adding domains

2. Cyc (“Sike”) Douglas Lenat, Cycorp Huge KB of common knowledge

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1. SUMO(Suggested Upper Merged Ontology)

Written in FOL Approx 1000 concepts in ontology Useful for basis of ‘expert’ projects

which do not need ‘common sense’ knowledge

Open source

SUMOBase ontology – top-level ontology

Entity

Physical Abstract

Object

SelfConnectedObject Region

ProcessQuantity

AttributeRelation

PropositionSetOrClass

Complete SUMO Ontology (PDF)

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SUMO

Example sub-ontology Units of Measure

PhysicalQuantity

UnitOfMeasure

SystemeInternationalUnitOfMeasure

ConstantQuantity

AngleMeasure

PlaneAngleMeasure

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SUMO

Equivalent to 2nd order power by treating functions, predicates, logical operators

as objects, also (not real examples)

F(x) (apply F x) (function)P(x,y) (holds P x y) (predicate)R(x) (instance x R) ( “ )( A B) (infer AND A B) (logical)

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SUMO example of logical - inverse(instance inverse BinaryPredicate)(instance inverse IrreflexiveRelation)(instance inverse IntransitiveRelation)(instance inverse SymmetricRelation)(domain inverse 1 BinaryRelation)(domain inverse 2 BinaryRelation)(=>

(inverse ?REL1 ?REL2)(forall (?INST1 ?INST2) (<=> (holds ?REL1 ?INST1 ?INST2) (holds ?REL2 ?INST2 ?INST1))))

EXAMPLE:(inverse greaterThan lessThan)

(subclass AnimacyAttribute BiologicalAttribute)(exhaustiveAttribute AnimacyAttribute Living Dead)(documentation AnimacyAttribute "&%Attributes that indicate whether an &%Organism is alive or not.")(instance Living AnimacyAttribute)(documentation Living "This &%Attribute applies to &%Organisms that are alive.")(=> (and (instance ?ORGANISM Organism) (agent ?PROCESS ?ORGANISM)) (holdsDuring (WhenFn ?PROCESS) (attribute ?ORGANISM Living)))(instance Dead AnimacyAttribute)(subAttribute Dead Unconscious)(contraryAttribute Dead Living)(documentation Dead "This &%Attribute applies to &%Organisms that are not alive.")(=> (instance ?ORG Organism) (exists (?ATTR) (and (instance ?ATTR AnimacyAttribute) (attribute ?ORG ?ATTR))))

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2. Cyc

enCYClopedia Douglas Lenat Cycorp 1984-> general knowledge

and common-sense reasoning

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Cyc (from cyc.com)

Ontology – 100,000’s of terms Millions of assertions

“Water is wet” “Everyone has a mother” “When you let go of things they usually

fall.” Open version available – opencyc.com

Description of ontology

on cyc website