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 A V A / x B F C = B F A / x C

Proof

Step Hyp Ref Expression
1 csbov12g A V A / x B F C = A / x B F A / x C
2 csbconstg A V A / x B = B
3 2 oveq1d A V A / x B F A / x C = B F A / x C
4 1 3 eqtrd A V A / x B F C = B F A / x C