Description: Version of cbv3h with two disjoint variable conditions, which does not require ax-11 nor ax-13 . (Contributed by BJ, 24-Jun-2019) (Proof modification is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | bj-cbv3hv2.nf | |- ( ps -> A. x ps ) | |
| bj-cbv3hv2.1 | |- ( x = y -> ( ph -> ps ) ) | ||
| Assertion | bj-cbv3hv2 | |- ( A. x ph -> A. y ps ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | bj-cbv3hv2.nf | |- ( ps -> A. x ps ) | |
| 2 | bj-cbv3hv2.1 | |- ( x = y -> ( ph -> ps ) ) | |
| 3 | 1 | nf5i | |- F/ x ps | 
| 4 | 3 2 | cbv3v2 | |- ( A. x ph -> A. y ps ) |