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 syl5eq ¬ F defAt A B A F B = V