Description: Move class substitution in and out of an operation. (Contributed by NM, 12-Nov-2005)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | csbov12g | ⊢ ( 𝐴 ∈ 𝑉 → ⦋ 𝐴 / 𝑥 ⦌ ( 𝐵 𝐹 𝐶 ) = ( ⦋ 𝐴 / 𝑥 ⦌ 𝐵 𝐹 ⦋ 𝐴 / 𝑥 ⦌ 𝐶 ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | csbov123 | ⊢ ⦋ 𝐴 / 𝑥 ⦌ ( 𝐵 𝐹 𝐶 ) = ( ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ⦋ 𝐴 / 𝑥 ⦌ 𝐹 ⦋ 𝐴 / 𝑥 ⦌ 𝐶 ) | |
| 2 | csbconstg | ⊢ ( 𝐴 ∈ 𝑉 → ⦋ 𝐴 / 𝑥 ⦌ 𝐹 = 𝐹 ) | |
| 3 | 2 | oveqd | ⊢ ( 𝐴 ∈ 𝑉 → ( ⦋ 𝐴 / 𝑥 ⦌ 𝐵 ⦋ 𝐴 / 𝑥 ⦌ 𝐹 ⦋ 𝐴 / 𝑥 ⦌ 𝐶 ) = ( ⦋ 𝐴 / 𝑥 ⦌ 𝐵 𝐹 ⦋ 𝐴 / 𝑥 ⦌ 𝐶 ) ) | 
| 4 | 1 3 | eqtrid | ⊢ ( 𝐴 ∈ 𝑉 → ⦋ 𝐴 / 𝑥 ⦌ ( 𝐵 𝐹 𝐶 ) = ( ⦋ 𝐴 / 𝑥 ⦌ 𝐵 𝐹 ⦋ 𝐴 / 𝑥 ⦌ 𝐶 ) ) |