Metamath Proof Explorer


Theorem fveqeq2d

Description: Equality deduction for function value. (Contributed by BJ, 30-Aug-2022)

Ref Expression
Hypothesis fveqeq2d.1 φ A = B
Assertion fveqeq2d φ F A = C F B = C

Proof

Step Hyp Ref Expression
1 fveqeq2d.1 φ A = B
2 1 fveq2d φ F A = F B
3 2 eqeq1d φ F A = C F B = C