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