MACM 101 Lecture 7: Lecture 7 Part 3_ Introduction Predicates and Quantifiers

• School: Simon Fraser University
• Department: Math & Comp Sci
• Course: MACM 101
• Professor: Andrei Bulatov

Document Summary

Lecture 7 part 3: introduction predicates and quantifiers. Asserts that a predicate is true for all values from the universe. X p(x) means that for every value a from the universe p(a) is true. Every car is grey" true! false! my car is not grey. X p(x) is false if and only if there is at least one value a from the universe such that. Such a value a is called a counterexample. Asserts that a predicate is true for at least one value from the universe. X p(x) means that there is a value a from the universe such that p(a) is true. "for some x, x^2 <0" true! my friend"s car is grey false! X p(x) is false if and only if for all a from the universe p(a) is false. For every value a from the universe p(a) is true. There is a counterexample a value a from the universe such that p(a) is false.