Description: Deduction for equality of operations. (Contributed by Zhi Wang, 19-Nov-2025)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | eqfnovd.1 | |- ( ph -> F Fn ( A X. B ) ) |
|
| eqfnovd.2 | |- ( ph -> G Fn ( A X. B ) ) |
||
| eqfnovd.3 | |- ( ( ph /\ ( x e. A /\ y e. B ) ) -> ( x F y ) = ( x G y ) ) |
||
| Assertion | eqfnovd | |- ( ph -> F = G ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eqfnovd.1 | |- ( ph -> F Fn ( A X. B ) ) |
|
| 2 | eqfnovd.2 | |- ( ph -> G Fn ( A X. B ) ) |
|
| 3 | eqfnovd.3 | |- ( ( ph /\ ( x e. A /\ y e. B ) ) -> ( x F y ) = ( x G y ) ) |
|
| 4 | 3 | ralrimivva | |- ( ph -> A. x e. A A. y e. B ( x F y ) = ( x G y ) ) |
| 5 | eqfnov2 | |- ( ( F Fn ( A X. B ) /\ G Fn ( A X. B ) ) -> ( F = G <-> A. x e. A A. y e. B ( x F y ) = ( x G y ) ) ) |
|
| 6 | 1 2 5 | syl2anc | |- ( ph -> ( F = G <-> A. x e. A A. y e. B ( x F y ) = ( x G y ) ) ) |
| 7 | 4 6 | mpbird | |- ( ph -> F = G ) |