Description: Equivalence of function value and ordered pair membership, analogous to funopfvb . (Contributed by Alexander van der Vekens, 25-May-2017)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | funopafvb | |- ( ( Fun F /\ A e. dom F ) -> ( ( F ''' A ) = B <-> <. A , B >. e. F ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | funfn | |- ( Fun F <-> F Fn dom F ) |
|
| 2 | fnopafvb | |- ( ( F Fn dom F /\ A e. dom F ) -> ( ( F ''' A ) = B <-> <. A , B >. e. F ) ) |
|
| 3 | 1 2 | sylanb | |- ( ( Fun F /\ A e. dom F ) -> ( ( F ''' A ) = B <-> <. A , B >. e. F ) ) |