Metamath Proof Explorer


Theorem feqmptd

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 ) ) )

Proof

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 ) ) )