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Set Theory

Explore key set theory principles including the definition of sets, subset criteria, and common set operations like union and intersection. This lesson helps you understand how these concepts apply within number theory to improve problem-solving skills in competitive programming.

Definition

A Set is an unordered collection of objects.

Eg: {2,3},{},{1,5,6}\{2, 3\}, \{\}, \{1, 5, 6\}

Objects don’t repeat in a set.

Unordered collection means the two sets {1,7,3}\{1,7,3\} and {7,1,3}\{7,1,3\} are equal.


Subsets

A set AA is subset of set BB (ABA \subset B) if ...