Metamath Proof Explorer


Theorem ifov

Description: Move a conditional outside of an operation. (Contributed by AV, 11-Nov-2019)

Ref Expression
Assertion ifov ( 𝐴 if ( 𝜑 , 𝐹 , 𝐺 ) 𝐵 ) = if ( 𝜑 , ( 𝐴 𝐹 𝐵 ) , ( 𝐴 𝐺 𝐵 ) )

Proof

Step Hyp Ref Expression
1 oveq ( if ( 𝜑 , 𝐹 , 𝐺 ) = 𝐹 → ( 𝐴 if ( 𝜑 , 𝐹 , 𝐺 ) 𝐵 ) = ( 𝐴 𝐹 𝐵 ) )
2 oveq ( if ( 𝜑 , 𝐹 , 𝐺 ) = 𝐺 → ( 𝐴 if ( 𝜑 , 𝐹 , 𝐺 ) 𝐵 ) = ( 𝐴 𝐺 𝐵 ) )
3 1 2 ifsb ( 𝐴 if ( 𝜑 , 𝐹 , 𝐺 ) 𝐵 ) = if ( 𝜑 , ( 𝐴 𝐹 𝐵 ) , ( 𝐴 𝐺 𝐵 ) )