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 F A = F B

Proof

Step Hyp Ref Expression
1 fveq2i.1 A = B
2 fveq2 A = B F A = F B
3 1 2 ax-mp F A = F B