Metamath Proof Explorer


Theorem fveq2i

Description: Equality inference for function value. (Contributed by NM, 28-Jul-1999)

Ref Expression
Hypothesis fveq2i.1 𝐴 = 𝐵
Assertion fveq2i ( 𝐹𝐴 ) = ( 𝐹𝐵 )

Proof

Step Hyp Ref Expression
1 fveq2i.1 𝐴 = 𝐵
2 fveq2 ( 𝐴 = 𝐵 → ( 𝐹𝐴 ) = ( 𝐹𝐵 ) )
3 1 2 ax-mp ( 𝐹𝐴 ) = ( 𝐹𝐵 )