Description: Variation of 19.29 . (Contributed by NM, 18-Aug-1993) (Proof shortened by Wolf Lammen, 12-Nov-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | 19.29r | |- ( ( E. x ph /\ A. x ps ) -> E. x ( ph /\ ps ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | pm3.21 | |- ( ps -> ( ph -> ( ph /\ ps ) ) ) |
|
2 | 1 | aleximi | |- ( A. x ps -> ( E. x ph -> E. x ( ph /\ ps ) ) ) |
3 | 2 | impcom | |- ( ( E. x ph /\ A. x ps ) -> E. x ( ph /\ ps ) ) |