| Step | Hyp | Ref
 | Expression | 
| 1 |   | eleq12 2261 | 
. . . . . . 7
⊢ ((𝑦 = {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ∧ 𝑦 = {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥}) → (𝑦 ∈ 𝑦 ↔ {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ∈ {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥})) | 
| 2 | 1 | anidms 397 | 
. . . . . 6
⊢ (𝑦 = {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} → (𝑦 ∈ 𝑦 ↔ {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ∈ {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥})) | 
| 3 | 2 | notbid 668 | 
. . . . 5
⊢ (𝑦 = {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} → (¬ 𝑦 ∈ 𝑦 ↔ ¬ {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ∈ {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥})) | 
| 4 |   | df-nel 2463 | 
. . . . . . 7
⊢ (𝑥 ∉ 𝑥 ↔ ¬ 𝑥 ∈ 𝑥) | 
| 5 |   | eleq12 2261 | 
. . . . . . . . 9
⊢ ((𝑥 = 𝑦 ∧ 𝑥 = 𝑦) → (𝑥 ∈ 𝑥 ↔ 𝑦 ∈ 𝑦)) | 
| 6 | 5 | anidms 397 | 
. . . . . . . 8
⊢ (𝑥 = 𝑦 → (𝑥 ∈ 𝑥 ↔ 𝑦 ∈ 𝑦)) | 
| 7 | 6 | notbid 668 | 
. . . . . . 7
⊢ (𝑥 = 𝑦 → (¬ 𝑥 ∈ 𝑥 ↔ ¬ 𝑦 ∈ 𝑦)) | 
| 8 | 4, 7 | bitrid 192 | 
. . . . . 6
⊢ (𝑥 = 𝑦 → (𝑥 ∉ 𝑥 ↔ ¬ 𝑦 ∈ 𝑦)) | 
| 9 | 8 | cbvrabv 2762 | 
. . . . 5
⊢ {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} = {𝑦 ∈ 𝐴 ∣ ¬ 𝑦 ∈ 𝑦} | 
| 10 | 3, 9 | elrab2 2923 | 
. . . 4
⊢ ({𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ∈ {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ↔ ({𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ∈ 𝐴 ∧ ¬ {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ∈ {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥})) | 
| 11 |   | pclem6 1385 | 
. . . 4
⊢ (({𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ∈ {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ↔ ({𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ∈ 𝐴 ∧ ¬ {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ∈ {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥})) → ¬ {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ∈ 𝐴) | 
| 12 | 10, 11 | ax-mp 5 | 
. . 3
⊢  ¬
{𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ∈ 𝐴 | 
| 13 |   | ssel 3177 | 
. . 3
⊢
(𝒫 𝐴 ⊆
𝐴 → ({𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ∈ 𝒫 𝐴 → {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ∈ 𝐴)) | 
| 14 | 12, 13 | mtoi 665 | 
. 2
⊢
(𝒫 𝐴 ⊆
𝐴 → ¬ {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ∈ 𝒫 𝐴) | 
| 15 |   | ssrab2 3268 | 
. . 3
⊢ {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ⊆ 𝐴 | 
| 16 |   | elpw2g 4189 | 
. . 3
⊢ (𝐴 ∈ 𝑉 → ({𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ∈ 𝒫 𝐴 ↔ {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ⊆ 𝐴)) | 
| 17 | 15, 16 | mpbiri 168 | 
. 2
⊢ (𝐴 ∈ 𝑉 → {𝑥 ∈ 𝐴 ∣ 𝑥 ∉ 𝑥} ∈ 𝒫 𝐴) | 
| 18 | 14, 17 | nsyl3 627 | 
1
⊢ (𝐴 ∈ 𝑉 → ¬ 𝒫 𝐴 ⊆ 𝐴) |