Description: Change bound variable in a restricted description binder. Version of cbvriotav with a disjoint variable condition, which does not require ax-13 . (Contributed by NM, 18-Mar-2013) (Revised by Gino Giotto, 26-Jan-2024)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | cbvriotavw.1 | |- ( x = y -> ( ph <-> ps ) ) |
|
| Assertion | cbvriotavw | |- ( iota_ x e. A ph ) = ( iota_ y e. A ps ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | cbvriotavw.1 | |- ( x = y -> ( ph <-> ps ) ) |
|
| 2 | nfv | |- F/ y ph |
|
| 3 | nfv | |- F/ x ps |
|
| 4 | 2 3 1 | cbvriotaw | |- ( iota_ x e. A ph ) = ( iota_ y e. A ps ) |