Proof of Theorem iinrab2
| Step | Hyp | Ref
| Expression |
| 1 | | iineq1 4990 |
. . . . . 6
⊢ (𝐴 = ∅ → ∩ 𝑥 ∈ 𝐴 {𝑦 ∈ 𝐵 ∣ 𝜑} = ∩
𝑥 ∈ ∅ {𝑦 ∈ 𝐵 ∣ 𝜑}) |
| 2 | | 0iin 5045 |
. . . . . 6
⊢ ∩ 𝑥 ∈ ∅ {𝑦 ∈ 𝐵 ∣ 𝜑} = V |
| 3 | 1, 2 | eqtrdi 2787 |
. . . . 5
⊢ (𝐴 = ∅ → ∩ 𝑥 ∈ 𝐴 {𝑦 ∈ 𝐵 ∣ 𝜑} = V) |
| 4 | 3 | ineq1d 4199 |
. . . 4
⊢ (𝐴 = ∅ → (∩ 𝑥 ∈ 𝐴 {𝑦 ∈ 𝐵 ∣ 𝜑} ∩ 𝐵) = (V ∩ 𝐵)) |
| 5 | | incom 4189 |
. . . . 5
⊢ (V ∩
𝐵) = (𝐵 ∩ V) |
| 6 | | inv1 4378 |
. . . . 5
⊢ (𝐵 ∩ V) = 𝐵 |
| 7 | 5, 6 | eqtri 2759 |
. . . 4
⊢ (V ∩
𝐵) = 𝐵 |
| 8 | 4, 7 | eqtrdi 2787 |
. . 3
⊢ (𝐴 = ∅ → (∩ 𝑥 ∈ 𝐴 {𝑦 ∈ 𝐵 ∣ 𝜑} ∩ 𝐵) = 𝐵) |
| 9 | | rzal 4489 |
. . . 4
⊢ (𝐴 = ∅ → ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐵 𝜑) |
| 10 | | rabid2 3454 |
. . . . 5
⊢ (𝐵 = {𝑦 ∈ 𝐵 ∣ ∀𝑥 ∈ 𝐴 𝜑} ↔ ∀𝑦 ∈ 𝐵 ∀𝑥 ∈ 𝐴 𝜑) |
| 11 | | ralcom 3274 |
. . . . 5
⊢
(∀𝑦 ∈
𝐵 ∀𝑥 ∈ 𝐴 𝜑 ↔ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐵 𝜑) |
| 12 | 10, 11 | bitr2i 276 |
. . . 4
⊢
(∀𝑥 ∈
𝐴 ∀𝑦 ∈ 𝐵 𝜑 ↔ 𝐵 = {𝑦 ∈ 𝐵 ∣ ∀𝑥 ∈ 𝐴 𝜑}) |
| 13 | 9, 12 | sylib 218 |
. . 3
⊢ (𝐴 = ∅ → 𝐵 = {𝑦 ∈ 𝐵 ∣ ∀𝑥 ∈ 𝐴 𝜑}) |
| 14 | 8, 13 | eqtrd 2771 |
. 2
⊢ (𝐴 = ∅ → (∩ 𝑥 ∈ 𝐴 {𝑦 ∈ 𝐵 ∣ 𝜑} ∩ 𝐵) = {𝑦 ∈ 𝐵 ∣ ∀𝑥 ∈ 𝐴 𝜑}) |
| 15 | | iinrab 5050 |
. . . 4
⊢ (𝐴 ≠ ∅ → ∩ 𝑥 ∈ 𝐴 {𝑦 ∈ 𝐵 ∣ 𝜑} = {𝑦 ∈ 𝐵 ∣ ∀𝑥 ∈ 𝐴 𝜑}) |
| 16 | 15 | ineq1d 4199 |
. . 3
⊢ (𝐴 ≠ ∅ → (∩ 𝑥 ∈ 𝐴 {𝑦 ∈ 𝐵 ∣ 𝜑} ∩ 𝐵) = ({𝑦 ∈ 𝐵 ∣ ∀𝑥 ∈ 𝐴 𝜑} ∩ 𝐵)) |
| 17 | | ssrab2 4060 |
. . . 4
⊢ {𝑦 ∈ 𝐵 ∣ ∀𝑥 ∈ 𝐴 𝜑} ⊆ 𝐵 |
| 18 | | dfss 3950 |
. . . 4
⊢ ({𝑦 ∈ 𝐵 ∣ ∀𝑥 ∈ 𝐴 𝜑} ⊆ 𝐵 ↔ {𝑦 ∈ 𝐵 ∣ ∀𝑥 ∈ 𝐴 𝜑} = ({𝑦 ∈ 𝐵 ∣ ∀𝑥 ∈ 𝐴 𝜑} ∩ 𝐵)) |
| 19 | 17, 18 | mpbi 230 |
. . 3
⊢ {𝑦 ∈ 𝐵 ∣ ∀𝑥 ∈ 𝐴 𝜑} = ({𝑦 ∈ 𝐵 ∣ ∀𝑥 ∈ 𝐴 𝜑} ∩ 𝐵) |
| 20 | 16, 19 | eqtr4di 2789 |
. 2
⊢ (𝐴 ≠ ∅ → (∩ 𝑥 ∈ 𝐴 {𝑦 ∈ 𝐵 ∣ 𝜑} ∩ 𝐵) = {𝑦 ∈ 𝐵 ∣ ∀𝑥 ∈ 𝐴 𝜑}) |
| 21 | 14, 20 | pm2.61ine 3016 |
1
⊢ (∩ 𝑥 ∈ 𝐴 {𝑦 ∈ 𝐵 ∣ 𝜑} ∩ 𝐵) = {𝑦 ∈ 𝐵 ∣ ∀𝑥 ∈ 𝐴 𝜑} |