Question

what is meant by set theory​

Answer 1

Set theory is the mathematical theory of well-determined collections, called sets, of objects that are called members, or elements, of the set. ... The axioms of set theory imply the existence of a set-theoretic universe so rich that all mathematical objects can be construed as sets.

Answer 2

Answer:

Set theory is the branch of mathematical logic that studies sets, which can be informally described as collections of objects. Although objects of any kind can be collected into a set, set theory, as a branch of mathematics, is mostly concerned with those that are relevant to mathematics as a whole.

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