Metamath Proof Explorer


Theorem fvmpt2df

Description: Deduction version of fvmpt2 . (Contributed by Glauco Siliprandi, 24-Jan-2025)

Ref Expression
Hypotheses fvmpt2df.1
|- F/_ x A
fvmpt2df.2
|- F = ( x e. A |-> B )
fvmpt2df.3
|- ( ( ph /\ x e. A ) -> B e. V )
Assertion fvmpt2df
|- ( ( ph /\ x e. A ) -> ( F ` x ) = B )

Proof

Step Hyp Ref Expression
1 fvmpt2df.1
 |-  F/_ x A
2 fvmpt2df.2
 |-  F = ( x e. A |-> B )
3 fvmpt2df.3
 |-  ( ( ph /\ x e. A ) -> B e. V )
4 2 fveq1i
 |-  ( F ` x ) = ( ( x e. A |-> B ) ` x )
5 id
 |-  ( x e. A -> x e. A )
6 1 fvmpt2f
 |-  ( ( x e. A /\ B e. V ) -> ( ( x e. A |-> B ) ` x ) = B )
7 5 3 6 syl2an2
 |-  ( ( ph /\ x e. A ) -> ( ( x e. A |-> B ) ` x ) = B )
8 4 7 eqtrid
 |-  ( ( ph /\ x e. A ) -> ( F ` x ) = B )