Metamath Proof Explorer


Theorem fveqeq2d

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

Ref Expression
Hypothesis fveqeq2d.1 φA=B
Assertion fveqeq2d φFA=CFB=C

Proof

Step Hyp Ref Expression
1 fveqeq2d.1 φA=B
2 1 fveq2d φFA=FB
3 2 eqeq1d φFA=CFB=C