Metamath Proof Explorer


Theorem oveq2

Description: Equality theorem for operation value. (Contributed by NM, 28-Feb-1995)

Ref Expression
Assertion oveq2 A=BCFA=CFB

Proof

Step Hyp Ref Expression
1 opeq2 A=BCA=CB
2 1 fveq2d A=BFCA=FCB
3 df-ov CFA=FCA
4 df-ov CFB=FCB
5 2 3 4 3eqtr4g A=BCFA=CFB