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Naïve Set Theory

Field: Set Theory

The study of naïve set theory.

Sequence of Expressions

Axiomatic set theory was developed in response to these early attempts to understand sets, with the goal of determining precisely what operations were allowed and when.
Intermediate
For any set AA, the set of all subsets of AA (the power set of AA) has a strictly greater cardinality than AA itself.\nP(A)>A|P(A)| > |A|
Sets are defined by a property P(x)P(x), i.e., S={xP(x)}S = \{x \mid P(x)\}. This allows for Russell's Paradox.