Metamath Proof Explorer


Theorem oveqd

Description: Equality deduction for operation value. (Contributed by NM, 9-Sep-2006)

Ref Expression
Hypothesis oveq1d.1 φ A = B
Assertion oveqd φ C A D = C B D

Proof

Step Hyp Ref Expression
1 oveq1d.1 φ A = B
2 oveq A = B C A D = C B D
3 1 2 syl φ C A D = C B D