Description: Deduction form of dffn5 . (Contributed by Mario Carneiro, 8-Jan-2015)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | feqmptd.1 | |- ( ph -> F : A --> B ) |
|
| Assertion | feqmptd | |- ( ph -> F = ( x e. A |-> ( F ` x ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | feqmptd.1 | |- ( ph -> F : A --> B ) |
|
| 2 | 1 | ffnd | |- ( ph -> F Fn A ) |
| 3 | dffn5 | |- ( F Fn A <-> F = ( x e. A |-> ( F ` x ) ) ) |
|
| 4 | 2 3 | sylib | |- ( ph -> F = ( x e. A |-> ( F ` x ) ) ) |