Metamath Proof Explorer


Theorem aovprc

Description: The value of an operation when the one of the arguments is a proper class, analogous to ovprc . (Contributed by Alexander van der Vekens, 26-May-2017)

Ref Expression
Hypothesis aovprc.1
|- Rel dom F
Assertion aovprc
|- ( -. ( A e. _V /\ B e. _V ) -> (( A F B )) = _V )

Proof

Step Hyp Ref Expression
1 aovprc.1
 |-  Rel dom F
2 df-aov
 |-  (( A F B )) = ( F ''' <. A , B >. )
3 df-br
 |-  ( A dom F B <-> <. A , B >. e. dom F )
4 1 brrelex12i
 |-  ( A dom F B -> ( A e. _V /\ B e. _V ) )
5 3 4 sylbir
 |-  ( <. A , B >. e. dom F -> ( A e. _V /\ B e. _V ) )
6 ndmafv
 |-  ( -. <. A , B >. e. dom F -> ( F ''' <. A , B >. ) = _V )
7 5 6 nsyl5
 |-  ( -. ( A e. _V /\ B e. _V ) -> ( F ''' <. A , B >. ) = _V )
8 2 7 syl5eq
 |-  ( -. ( A e. _V /\ B e. _V ) -> (( A F B )) = _V )