Metamath Proof Explorer


Theorem rnfvprc

Description: The range of a function value at a proper class is empty. (Contributed by AV, 20-Aug-2022)

Ref Expression
Hypothesis rnfvprc.y Y = F X
Assertion rnfvprc ¬ X V ran Y =

Proof

Step Hyp Ref Expression
1 rnfvprc.y Y = F X
2 fvprc ¬ X V F X =
3 1 2 eqtrid ¬ X V Y =
4 3 rneqd ¬ X V ran Y = ran
5 rn0 ran =
6 4 5 eqtrdi ¬ X V ran Y =