Description: Axiom of Union. An axiom
of Zermelo-Fraenkel set theory. It states
that a set exists
that includes the union of a given set
i.e. the collection of all members of the members of . The
variant axun2 2859 states that the union itself exists. A
version with
the standard abbreviation for union is uniex2 2860. A version using class
notation is uniex 2861.
The union of a class df-uni 2494 should not be confused with the union of
two classes df-un 2040. Their relationship is shown in unipr 2505. |