Metamath Proof Explorer


Theorem afveq1

Description: Equality theorem for function value, analogous to fveq1 . (Contributed by Alexander van der Vekens, 22-Jul-2017)

Ref Expression
Assertion afveq1 ( 𝐹 = 𝐺 → ( 𝐹 ''' 𝐴 ) = ( 𝐺 ''' 𝐴 ) )

Proof

Step Hyp Ref Expression
1 id ( 𝐹 = 𝐺𝐹 = 𝐺 )
2 eqidd ( 𝐹 = 𝐺𝐴 = 𝐴 )
3 1 2 afveq12d ( 𝐹 = 𝐺 → ( 𝐹 ''' 𝐴 ) = ( 𝐺 ''' 𝐴 ) )