Description: Bound-variable hypothesis builder for the iota class. Version of nfiota with a disjoint variable condition, which does not require ax-13 . (Contributed by NM, 23-Aug-2011) (Revised by Gino Giotto, 26-Jan-2024)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | nfiotaw.1 | |- F/ x ph |
|
| Assertion | nfiotaw | |- F/_ x ( iota y ph ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | nfiotaw.1 | |- F/ x ph |
|
| 2 | nftru | |- F/ y T. |
|
| 3 | 1 | a1i | |- ( T. -> F/ x ph ) |
| 4 | 2 3 | nfiotadw | |- ( T. -> F/_ x ( iota y ph ) ) |
| 5 | 4 | mptru | |- F/_ x ( iota y ph ) |