CMPUT272 Lecture Notes - Lecture 6: Contraposition

• School: University of Alberta
• Department: Computing Science
• Course: CMPUT272
• Professor: Lorna Stewart

Document Summary

Propositional logic inverse converse contrapositive negation tautology p q p q p p (p q) p h x is even or x is odd but not both e: x is even o: x is odd (e o) Rex is not a westie if he"s not a dog. But that implies that a is a knight, a. Then, (a is a knight) b is a knight. Then, (a is a knight) b is a knight a a y l(x, y) set of all integers 5 a a y l(x, y) set of all integers 5. "forall" example: for all x in a domain d, s(x) is true example: for all x in a domain d, s(x) is true. True if and only if s(x) for every x of the domain. "forsome" example: for some x in a domain d, s(x) is true example: for some x in a domain d, s(x) is true.