Metamath Proof Explorer


Theorem fveq2d

Description: Equality deduction for function value. (Contributed by NM, 29-May-1999)

Ref Expression
Hypothesis fveq2d.1 φ A = B
Assertion fveq2d φ F A = F B

Proof

Step Hyp Ref Expression
1 fveq2d.1 φ A = B
2 fveq2 A = B F A = F B
3 1 2 syl φ F A = F B