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 ) |