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Chapter 5 Sets
Objectives
Recognize whether a collection of objects is well-defined.
Recognize whether an element is in a set.
Rewrite a given set in roster form.
Recognize when two sets are equal.
We use the word set every day — a set of books, a set of dishes, a set of rules. In mathematics, we often need to state exactly which objects are part of a problem. We already discussed an important mathematical
set — the set of integers, even though we did not use the word set.
We formally define the term set and give different ways to describe sets. We introduce notation for membership in a set and for stating when two sets are equal. We also give symbols for special sets such as the empty set and the set of integers.
