Metamath Proof Explorer


Theorem fvclex

Description: Existence of the class of values of a set. (Contributed by NM, 9-Nov-1995)

Ref Expression
Hypothesis fvclex.1 F V
Assertion fvclex y | x y = F x V

Proof

Step Hyp Ref Expression
1 fvclex.1 F V
2 1 rnex ran F V
3 snex V
4 2 3 unex ran F V
5 fvclss y | x y = F x ran F
6 4 5 ssexi y | x y = F x V