Metamath Proof Explorer


Theorem dmex

Description: The domain of a set is a set. Corollary 6.8(2) of TakeutiZaring p. 26. (Contributed by NM, 7-Jul-2008)

Ref Expression
Hypothesis dmex.1 AV
Assertion dmex domAV

Proof

Step Hyp Ref Expression
1 dmex.1 AV
2 dmexg AVdomAV
3 1 2 ax-mp domAV