Description: Obsolete version of f1odm as of 10-Jun-2026. (Contributed by NM, 8-Mar-2014) (Proof modification is discouraged.) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | f1odmOLD | |- ( F : A -1-1-onto-> B -> dom F = A ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | f1ofn | |- ( F : A -1-1-onto-> B -> F Fn A ) |
|
| 2 | fndm | |- ( F Fn A -> dom F = A ) |
|
| 3 | 1 2 | syl | |- ( F : A -1-1-onto-> B -> dom F = A ) |