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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