Set (mathematics)

In <a href="/facts/Mathematics/pxTouaz4">mathematics</a>, a set is a collection of different things; the things are <a href="/facts/Element_(mathematics)/Q2mx1vHL">elements</a> or members of the set and are typically <a href="/facts/Mathematical_object/Juhyow9M">mathematical objects</a>: numbers, symbols, points in space, lines, other <a href="/facts/Geometric_shape/nww0x85d">geometric shapes</a>, variables, or other sets. A set may be <a href="/facts/Finite_set/za1newlP">finite</a> or <a href="/facts/Infinite_set/9rTN0xGH">infinite</a>. There is a unique set with no elements, called the <a href="/facts/Empty_set/ffEk3eA6">empty set</a>; a set with a single element is a <a href="/facts/Singleton_(mathematics)/LtNVfujT">singleton</a>. 
Sets are ubiquitous in modern mathematics. Indeed, <a href="/facts/Set_theory/1ptfsvUP">set theory</a>, more specifically <a href="/facts/Zermelo%25E2%2580%2593Fraenkel_set_theory/UYIsPbXw">Zermelo–Fraenkel set theory</a>, has been the standard way to provide rigorous <a href="/facts/Foundations_of_mathematics/yjpbbUkt">foundations</a> for all branches of mathematics since the first half of the 20th century.

Set (mathematics) open-in-new

Set (mathematics)