Metamath Proof Explorer


Theorem fveq12i

Description: Equality deduction for function value. (Contributed by FL, 27-Jun-2014)

Ref Expression
Hypotheses fveq12i.1
|- F = G
fveq12i.2
|- A = B
Assertion fveq12i
|- ( F ` A ) = ( G ` B )

Proof

Step Hyp Ref Expression
1 fveq12i.1
 |-  F = G
2 fveq12i.2
 |-  A = B
3 1 fveq1i
 |-  ( F ` A ) = ( G ` A )
4 2 fveq2i
 |-  ( G ` A ) = ( G ` B )
5 3 4 eqtri
 |-  ( F ` A ) = ( G ` B )