Description: Preimage of a difference. (Contributed by Mario Carneiro, 14-Jun-2016)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | difpreima | |- ( Fun F -> ( `' F " ( A \ B ) ) = ( ( `' F " A ) \ ( `' F " B ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | funcnvcnv | |- ( Fun F -> Fun `' `' F ) |
|
| 2 | imadif | |- ( Fun `' `' F -> ( `' F " ( A \ B ) ) = ( ( `' F " A ) \ ( `' F " B ) ) ) |
|
| 3 | 1 2 | syl | |- ( Fun F -> ( `' F " ( A \ B ) ) = ( ( `' F " A ) \ ( `' F " B ) ) ) |