Metamath Proof Explorer


Theorem oveq12

Description: Equality theorem for operation value. (Contributed by NM, 16-Jul-1995)

Ref Expression
Assertion oveq12 A=BC=DAFC=BFD

Proof

Step Hyp Ref Expression
1 oveq1 A=BAFC=BFC
2 oveq2 C=DBFC=BFD
3 1 2 sylan9eq A=BC=DAFC=BFD