Metamath Proof Explorer


Theorem aovnfundmuv

Description: If an ordered pair is not in the domain of a class or the class is not a function restricted to the ordered pair, then the operation value for this pair is the universal class. (Contributed by Alexander van der Vekens, 26-May-2017)

Ref Expression
Assertion aovnfundmuv ⊢ ¬ F defAt A B → A F B = V

Proof

Step Hyp Ref Expression
1 df-aov ⊢ A F B = F ''' A B
2 afvnfundmuv ⊢ ¬ F defAt A B → F ''' A B = V
3 1 2 eqtrid ⊢ ¬ F defAt A B → A F B = V