Description: Version of stdpc5 with a disjoint variable condition, requiring fewer axioms. (Contributed by BJ, 7-Mar-2020) Revised to shorten 19.21v . (Revised by Wolf Lammen, 12-Jul-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | stdpc5v | |- ( A. x ( ph -> ps ) -> ( ph -> A. x ps ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ax-5 | |- ( ph -> A. x ph ) |
|
2 | alim | |- ( A. x ( ph -> ps ) -> ( A. x ph -> A. x ps ) ) |
|
3 | 1 2 | syl5 | |- ( A. x ( ph -> ps ) -> ( ph -> A. x ps ) ) |