Description: Version of nfal with an 'h' hypothesis, avoiding ax-12 . (Contributed by SN, 11-Feb-2026)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | nfalh.1 | |- ( ph -> A. x ph ) |
|
| Assertion | nfalh | |- F/ x A. y ph |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | nfalh.1 | |- ( ph -> A. x ph ) |
|
| 2 | 1 | hbal | |- ( A. y ph -> A. x A. y ph ) |
| 3 | 2 | nf5i | |- F/ x A. y ph |