Metamath Proof Explorer


Theorem ovif

Description: Move a conditional outside of an operation. (Contributed by Thierry Arnoux, 25-Jan-2017)

Ref Expression
Assertion ovif ifφABFC=ifφAFCBFC

Proof

Step Hyp Ref Expression
1 oveq1 ifφAB=AifφABFC=AFC
2 oveq1 ifφAB=BifφABFC=BFC
3 1 2 ifsb ifφABFC=ifφAFCBFC