What is "universal set"

n. (context set theory English) A set large enough to contain all sets under consideration in the current context.

In set theory, a universal set is a set which contains all objects, including itself. In set theory as usually formulated, the conception of a universal set leads to a paradox ( Russell's paradox) and is consequently not allowed. However, some non-standard variants of set theory include a universal set. It is often symbolized by the Greek letter xi.

Universal set may refer to: