Metamath Proof Explorer


Theorem oveq12d

Description: Equality deduction for operation value. (Contributed by NM, 13-Mar-1995) (Proof shortened by Andrew Salmon, 22-Oct-2011)

Ref Expression
Hypotheses oveq1d.1 φA=B
oveq12d.2 φC=D
Assertion oveq12d φAFC=BFD

Proof

Step Hyp Ref Expression
1 oveq1d.1 φA=B
2 oveq12d.2 φC=D
3 oveq12 A=BC=DAFC=BFD
4 1 2 3 syl2anc φAFC=BFD