Description: Deduction doubly quantifying both antecedent and consequent, based on Theorem 19.20 of Margaris p. 90 ( alim ). (Contributed by AV, 27-Nov-2019)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | ralimdvva.1 | |- ( ( ph /\ ( x e. A /\ y e. B ) ) -> ( ps -> ch ) ) | |
| Assertion | ralimdvva | |- ( ph -> ( A. x e. A A. y e. B ps -> A. x e. A A. y e. B ch ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | ralimdvva.1 | |- ( ( ph /\ ( x e. A /\ y e. B ) ) -> ( ps -> ch ) ) | |
| 2 | 1 | anassrs | |- ( ( ( ph /\ x e. A ) /\ y e. B ) -> ( ps -> ch ) ) | 
| 3 | 2 | ralimdva | |- ( ( ph /\ x e. A ) -> ( A. y e. B ps -> A. y e. B ch ) ) | 
| 4 | 3 | ralimdva | |- ( ph -> ( A. x e. A A. y e. B ps -> A. x e. A A. y e. B ch ) ) |