Mathematics 1228A/B Lecture Notes - Lecture 1: Empty Set, Rock Records, 5,6,7,8

• School: Western University
• Department: Mathematics
• Course: Mathematics 1228A/B
• Professor: Arash Pourkia

Document Summary

A set is just a collection of possibly zero, possibly infinitely many objects. There are 3 basic ways to describe a set: list out the things in the set. Ex: {john, paul, george, ringo} (the beatles: list using a pattern. Ex: {alabama, alaska wyoming} (alphabet order: describe the using languages. Ex1: the set that contains all canadians who vote ndp, the last election. Ex2: the set of prime numbers between 10000 and 100000. Usually we label sets with capital letters: a, b, c. There is one set that has a special name: the empty set. This is the set with zero objects in it: or {} Ex: let p be the set of inner planets, write our p. Sets on their own are state and boring , what we want is to describe bigger and more complex sets, and we"ll often create them from simpler sets. There are 3 basic operations that take old sets and make new sets.