Description: Inference from Theorem 19.21 of Margaris p. 90. (Restricted quantifier version with double quantification.) (Contributed by NM, 2-Feb-2008)
Ref | Expression | ||
---|---|---|---|
Hypothesis | ralrimdvva.1 | |- ( ( ph /\ ( x e. A /\ y e. B ) ) -> ( ps -> ch ) ) |
|
Assertion | ralrimdvva | |- ( ph -> ( ps -> A. x e. A A. y e. B ch ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ralrimdvva.1 | |- ( ( ph /\ ( x e. A /\ y e. B ) ) -> ( ps -> ch ) ) |
|
2 | 1 | ex | |- ( ph -> ( ( x e. A /\ y e. B ) -> ( ps -> ch ) ) ) |
3 | 2 | com23 | |- ( ph -> ( ps -> ( ( x e. A /\ y e. B ) -> ch ) ) ) |
4 | 3 | ralrimdvv | |- ( ph -> ( ps -> A. x e. A A. y e. B ch ) ) |