Metamath Proof Explorer


Theorem csbov2g

Description: Move class substitution in and out of an operation. (Contributed by NM, 12-Nov-2005)

Ref Expression
Assertion csbov2g AVA/xBFC=BFA/xC

Proof

Step Hyp Ref Expression
1 csbov12g AVA/xBFC=A/xBFA/xC
2 csbconstg AVA/xB=B
3 2 oveq1d AVA/xBFA/xC=BFA/xC
4 1 3 eqtrd AVA/xBFC=BFA/xC