Copyright © 2002 Cycorp Writing Efficient CycL: Part 2 Part One: General Suggestions –Simpler is Better –Use Rule Macro Predicates –Create Simplifying Vocabulary Part Two: Cyc-Specific Suggestions –Factor out Commonality –Existence is Expensive –Exceptions are Exceptional –State Negations Explicitly –Generalize -- Don’t List –Use #$different
Copyright © 2002 Cycorp Writing Efficient CycL: Part 2 Factor out Commonality Existence is Expensive Exceptions are Exceptional State Negations Explicitly Generalize -- Don’t List Use #$different
Copyright © 2002 Cycorp N*M reduces to N+M When similarity is not a coincidence N*M reduces to N+M A B C D W X Y Z P A B C D W X Y Z
Copyright © 2002 Cycorp Commonalities in Collections Olympic Men’s Individual 400 Meter Butterfly Olympic Women’s Individual 100 Meter Backstroke Olympic Women’s Individual 200 Meter Freestyle Olympic Men’s Individual 200 Meter Backstroke
Copyright © 2002 Cycorp Commonalities in Collections Olympic Competition Individual Competition Swimming Competition Olympic Men’s Individual 400 Meter Butterfly Olympic Women’s Individual 100 Meter Backstroke Olympic Women’s Individual 200 Meter Freestyle Olympic Men’s Individual 200 Meter Backstroke
Copyright © 2002 Cycorp Commonalities in Collections Olympic Competition Individual Competition Swimming Competition Olympic Men’s Individual 400 Meter Butterfly Olympic Women’s Individual 100 Meter Backstroke Olympic Women’s Individual 200 Meter Freestyle Olympic Men’s Individual 200 Meter Backstroke
Copyright © 2002 Cycorp Commonalities in Collections Olympic Competition Individual Competition Swimming Competition Olympic Men’s Individual 400 Meter Butterfly Olympic Women’s Individual 100 Meter Backstroke Olympic Women’s Individual 200 Meter Freestyle Olympic Men’s Individual 200 Meter Backstroke Olympic Individual Swimming
Copyright © 2002 Cycorp Commonalities in Microtheories April 15, 2002 USA Today Sports Section Mt June 2, 2002 USA Today Sports Section Mt October 8, 2002 USA Today Sports Section Mt September 21, 2002 USA Today Sports Section Mt...
Copyright © 2002 Cycorp Commonalities in Microtheories Rules for Games Mt American Sports Competition Mt Current and Historical Stats Mt April 15, 2002 USA Today Sports Section Mt June 2, 2002 USA Today Sports Section Mt October 8, 2002 USA Today Sports Section Mt September 21, 2002 USA Today Sports Section Mt
Copyright © 2002 Cycorp Commonalities in Microtheories April 15, 2002 USA Today Sports Section Mt June 2, 2002 USA Today Sports Section Mt October 8, 2002 USA Today Sports Section Mt September 21, 2002 USA Today Sports Section Mt Rules for Games Mt American Sports Competition Mt Current and Historical Stats Mt
Copyright © 2002 Cycorp Commonalities in Microtheories Rules, Competition, and Stats Mt April 15, 2002 USA Today Sports Section Mt June 2, 2002 USA Today Sports Section Mt October 8, 2002 USA Today Sports Section Mt September 21, 2002 USA Today Sports Section Mt Rules for Games Mt American Sports Competition Mt Current and Historical Stats Mt
Copyright © 2002 Cycorp Microtheories + a Forward Rule XYT A Z PQR S S PQR
Copyright © 2002 Cycorp Microtheories + a Forward Rule XYTZ PQR S C S D S A S B S... PQR
Copyright © 2002 Cycorp T PQR S... S Shared Assumptions Mt Microtheories + a Forward Rule XYZ C DA B PQR
Copyright © 2002 Cycorp Writing Efficient CycL: Part 2 Factor out Commonality Existence is Expensive Exceptions are Exceptional State Negations Explicitly Generalize -- Don’t List Use #$different
Copyright © 2002 Cycorp Concluding #$thereExists Skolemization –In order to conclude #$thereExists, introduce a function to denote the thing that so exists so that we can reason with it –Extends the number of concepts and symbols in the language that the system might have to think about –Things that conclude #$thereExists are a little more expensive than others
Copyright © 2002 Cycorp State Existence Generally Pervasive problem Every elephant has a head Every elephant has a head with a trunk Every cat has a head with whiskers Every spotted wombat has a spotted head … State existence generally, constrain specifically Every animal has a head Every elephant has a trunk An animal’s trunk is part of its head
Copyright © 2002 Cycorp Writing Efficient CycL: Part 2 Factor out Commonality Existence is Expensive Exceptions are Exceptional State Negations Explicitly Generalize -- Don’t List Use #$different
Copyright © 2002 Cycorp Overuse of #$not (#$implies (#$and (#$isa ?BRD #$Bird) (#$not (#$isa ?BRD #$Penguin))) (#$behaviorCapableOf ?BRD #$Flying #$performedBy)) What about Emus? What about these examples? –broken wings –feet in concrete –slathered in crude oil –hypnotized into thinking it is a dog
Copyright © 2002 Cycorp Use Default Reasoning Solution : use default reasoning (#$implies (#$isa ?BRD #$Bird) (#$behaviorCapableOf ?BRD #$Flying #$performedBy)) (#$exceptWhen (#$isa ?BRD #$FlightlessBird) (#$implies (#$isa ?BRD #$Bird) (#$behaviorCapableOf ?BRD #$Flying #$performedBy))) (#$genls #$Penguin #$FlightlessBird) (#$genls #$Emu #$FlightlessBird)...
Copyright © 2002 Cycorp Postpone Checking for Exceptions Save a lot of work –only check for exceptional cases after using the rule #$not ’s in the antecedent of a rule you’re writing? –ask yourself “is this what the rule really means or this a meta-statement about cases where that rule wouldn’t apply and should be stated as an exception?”
Copyright © 2002 Cycorp Writing Efficient CycL: Part 2 Factor out Commonality Existence is Expensive Exceptions are Exceptional State Negations Explicitly Generalize -- Don’t List Use #$different
Copyright © 2002 Cycorp Underuse of #$not Better to conclude than assume Negations can prune inferences Some Powerful Negations #$ disjointWith is not a ( #$disjointWith )
Copyright © 2002 Cycorp Powerful Negations #$SiblingDisjointCollection #$completeExtentKnown is not a ( #$SiblingDisjointCollection ) is not a ( #$SiblingDisjointCollection ) (#$completeExtentKnown #$nationalBorder)
Copyright © 2002 Cycorp Another Powerful Negation #$completeCollectionExtent (#$completeCollectionExtent #$MonthOfYearType) #$January, #$February, #$March, #$April, #$May, #$June, #$July, #$August, #$September, #$October, #$November, #$December + #$Yule ?
Copyright © 2002 Cycorp Writing Efficient CycL: Part 2 Factor out Commonality Existence is Expensive Exceptions are Exceptional State Negations Explicitly Generalize -- Don’t List Use #$different
Copyright © 2002 Cycorp Disjunctions? Try to Generalize “list-em” KR is almost always wrong (#$implies (#$and (#$isa ?PRSN #$Person) (#$or (#$brothers ?PRSN ?SBLNG) (#$sisters ?PRSN ?SBLNG))) (#$feelsTowardsObject ?PRSN ?SBLNG #$Rivalry #$Positive)) Create vocabulary for the generalization #$siblings
Copyright © 2002 Cycorp Writing Efficient CycL: Part 2 Factor out Commonality Existence is Expensive Exceptions are Exceptional State Negations Explicitly Generalize -- Don’t List Use #$different
Copyright © 2002 Cycorp Use #$different Avoid (#$not (#$equals...)) (#$different...) is much better than (#$and(#$not (#$equals )) (#$not (#$equals ))...)
Copyright © 2002 Cycorp Summary Factor out Commonality Existence is Expensive Exceptions are Exceptional State Negations Explicitly Generalize - Don’t List Use #$different Avoid (#$not (#$equals...))