Description: A one-to-one function maps one-to-one onto its range. (Contributed by NM, 4-Sep-2004)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | f1f1orn | |- ( F : A -1-1-> B -> F : A -1-1-onto-> ran F ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | f1fn | |- ( F : A -1-1-> B -> F Fn A ) |
|
| 2 | df-f1 | |- ( F : A -1-1-> B <-> ( F : A --> B /\ Fun `' F ) ) |
|
| 3 | 2 | simprbi | |- ( F : A -1-1-> B -> Fun `' F ) |
| 4 | f1orn | |- ( F : A -1-1-onto-> ran F <-> ( F Fn A /\ Fun `' F ) ) |
|
| 5 | 1 3 4 | sylanbrc | |- ( F : A -1-1-> B -> F : A -1-1-onto-> ran F ) |