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=BFA=FB
3 1 2 ax-mp FA=FB