set theory

branch of mathematics that deals with the grouping of theorems and proving them

Set theory is the mathematical theory of sets, which represent collections of abstract objects. It encompasses the everyday notions, introduced in primary school, often as Venn diagrams, of collections of objects, and the elements of, and membership in, such collections. In most modern mathematical formalisms, set theory provides the language in which mathematical objects are described. It is (along with logic and the predicate calculus) one of the axiomatic foundations for mathematics, allowing mathematical objects to be constructed formally from the undefined terms of "set" and "set membership". It is in its own right a branch of mathematics and an active field of mathematical research.
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Noun
1. the branch of pure mathematics that deals with the nature and relations of sets
(hypernym) pure mathematics
(classification) mathematics, math, maths

union 

<mathematics> A mathematical formalisation of the theory of "sets" (aggregates or collections) of objects ("elements" or "members"). Many mathematicians use set theory as the basis for all other mathematics.
Mathematicians began to realise toward the end of the 19th century that just doing "the obvious thing" with sets led to embarrassing 

Eng: set theory
Urdu: نَظَریہ سیٹ ۔ نظریہ مجموع ۔ ریاضی ۔ کی وہ شاخ جو مجموعُوں کے باہمی تعلقات سے سروکار رکھتی ہے ۔