Description: Composition of an injective function with its converse. (Contributed by FL, 11-Nov-2011)
Ref | Expression | ||
---|---|---|---|
Assertion | f1cocnv1 | |- ( F : A -1-1-> B -> ( `' F o. F ) = ( _I |` A ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | f1f1orn | |- ( F : A -1-1-> B -> F : A -1-1-onto-> ran F ) |
|
2 | f1ococnv1 | |- ( F : A -1-1-onto-> ran F -> ( `' F o. F ) = ( _I |` A ) ) |
|
3 | 1 2 | syl | |- ( F : A -1-1-> B -> ( `' F o. F ) = ( _I |` A ) ) |