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CSE4/563: Knowledge Representation Recitation October 6, 2010.
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CSE4/563: Knowledge RepresentationRecitation October 6, 2010 “If every tool, when ordered, or even of its own accord, could do the work that befits it, just as the creations of Daedalus moved of themselves . . . If the weavers' shuttles were to weave of themselves, then there would be no need either of apprentices for the master workers or of slaves for the lords” --Aristotle
HW3/Proj1 Questions/Concerns? http://www.cse.buffalo.edu/~shapiro/Courses/CSE563/2010/Homeworks/hw3.pdf http://www.cse.buffalo.edu/~shapiro/Courses/CSE563/2010/Projects/proj1.pdf
Recitation Website • http://danielschlegel.org/pages/teaching.htm
Clause Form Propositional Logic • P <=> q |- (p=>q) ^ (q=>p) • Convert to clause form • Do resolution refutation (trivial)
Resolution Refutation • ((p->q) ^ (r->s) ^ (p v r)) |- q v s • Known as the “Constructive Dilemma” We can think of this in our Dorothy world as: • (DorothyHasToFindToto->InOz)^ MakesToCellar->TakesAWalkWithTotoInKansas ^ (DorothyHasToFindToto v MakesToCellar)) |- (InOz v TakesAWalkWithTotoInKansas)
Resources • If you’re looking for more problems to practice with, one place to look is: • http://en.wikipedia.org/wiki/Propositional_calculus
Terminology Review • Term • Predicate • Proposition • Formula • Open • Closed • Ground
Terminology Practice • Drives(Betty, y) • Is this a term, predicate, proposition, or formula? • Is “Drives” a term, predicate, proposition, or formula? • Is “Betty” a term, predicate, proposition, or formula? • Is “y” a term, predicate, proposition, or formula?
Terminology Practice • Drives(Betty, y) • Is this a term, predicate, proposition, or formula? • Is “Drives” a term, predicate, proposition, or formula? • Is “Betty” a term, predicate, proposition, or formula? • Is “y” a term, predicate, proposition, or formula? • TomDrivesBetty • Is this a term, predicate, proposition, or formula?