CIS 1166 Lecture Notes - Set-Builder Notation, Empty Set, Subset

• School: Temple University
• Department: Computer & Information Science
• Course: CIS 1166
• Professor: Schulman

Document Summary

This note is a summary of some material related to sets, material discussed in. Neither i nor rosen provide a formal de nition of sets. There are some tricky problems that arise if one tries to be very strict and formal, but for our purposes it su ces to use the intuitive notion of a set as a collection of things. The kind of things that we put together in the same collection can be very disparate. We can have a set consisting of just the number 4, charles de gaulle"s favorite song and whatever thoughts. George w. bush is currently thinking at this very second. If our set is small enough, we can actually list all the elements in our set. To do so, we use the notation illustrated below: Here i have speci ed that a is a six element set with members 3, 8, 12, 23,