| Step | Hyp | Ref
| Expression |
| 1 | | difeq2 4120 |
. . . . . . 7
⊢ (𝑢 = 𝑥 → (𝐴 ∖ 𝑢) = (𝐴 ∖ 𝑥)) |
| 2 | 1 | eleq1d 2826 |
. . . . . 6
⊢ (𝑢 = 𝑥 → ((𝐴 ∖ 𝑢) ∈ 𝑌 ↔ (𝐴 ∖ 𝑥) ∈ 𝑌)) |
| 3 | 2 | elrab 3692 |
. . . . 5
⊢ (𝑥 ∈ {𝑢 ∈ 𝒫 𝐴 ∣ (𝐴 ∖ 𝑢) ∈ 𝑌} ↔ (𝑥 ∈ 𝒫 𝐴 ∧ (𝐴 ∖ 𝑥) ∈ 𝑌)) |
| 4 | | difeq2 4120 |
. . . . . . 7
⊢ (𝑢 = 𝑦 → (𝐴 ∖ 𝑢) = (𝐴 ∖ 𝑦)) |
| 5 | 4 | eleq1d 2826 |
. . . . . 6
⊢ (𝑢 = 𝑦 → ((𝐴 ∖ 𝑢) ∈ 𝑌 ↔ (𝐴 ∖ 𝑦) ∈ 𝑌)) |
| 6 | 5 | elrab 3692 |
. . . . 5
⊢ (𝑦 ∈ {𝑢 ∈ 𝒫 𝐴 ∣ (𝐴 ∖ 𝑢) ∈ 𝑌} ↔ (𝑦 ∈ 𝒫 𝐴 ∧ (𝐴 ∖ 𝑦) ∈ 𝑌)) |
| 7 | | an4 656 |
. . . . . 6
⊢ (((𝑥 ∈ 𝒫 𝐴 ∧ (𝐴 ∖ 𝑥) ∈ 𝑌) ∧ (𝑦 ∈ 𝒫 𝐴 ∧ (𝐴 ∖ 𝑦) ∈ 𝑌)) ↔ ((𝑥 ∈ 𝒫 𝐴 ∧ 𝑦 ∈ 𝒫 𝐴) ∧ ((𝐴 ∖ 𝑥) ∈ 𝑌 ∧ (𝐴 ∖ 𝑦) ∈ 𝑌))) |
| 8 | 7 | biimpi 216 |
. . . . 5
⊢ (((𝑥 ∈ 𝒫 𝐴 ∧ (𝐴 ∖ 𝑥) ∈ 𝑌) ∧ (𝑦 ∈ 𝒫 𝐴 ∧ (𝐴 ∖ 𝑦) ∈ 𝑌)) → ((𝑥 ∈ 𝒫 𝐴 ∧ 𝑦 ∈ 𝒫 𝐴) ∧ ((𝐴 ∖ 𝑥) ∈ 𝑌 ∧ (𝐴 ∖ 𝑦) ∈ 𝑌))) |
| 9 | 3, 6, 8 | syl2anb 598 |
. . . 4
⊢ ((𝑥 ∈ {𝑢 ∈ 𝒫 𝐴 ∣ (𝐴 ∖ 𝑢) ∈ 𝑌} ∧ 𝑦 ∈ {𝑢 ∈ 𝒫 𝐴 ∣ (𝐴 ∖ 𝑢) ∈ 𝑌}) → ((𝑥 ∈ 𝒫 𝐴 ∧ 𝑦 ∈ 𝒫 𝐴) ∧ ((𝐴 ∖ 𝑥) ∈ 𝑌 ∧ (𝐴 ∖ 𝑦) ∈ 𝑌))) |
| 10 | | sorpssi 7749 |
. . . . . . . 8
⊢ ((
[⊊] Or 𝑌
∧ ((𝐴 ∖ 𝑥) ∈ 𝑌 ∧ (𝐴 ∖ 𝑦) ∈ 𝑌)) → ((𝐴 ∖ 𝑥) ⊆ (𝐴 ∖ 𝑦) ∨ (𝐴 ∖ 𝑦) ⊆ (𝐴 ∖ 𝑥))) |
| 11 | 10 | expcom 413 |
. . . . . . 7
⊢ (((𝐴 ∖ 𝑥) ∈ 𝑌 ∧ (𝐴 ∖ 𝑦) ∈ 𝑌) → ( [⊊] Or 𝑌 → ((𝐴 ∖ 𝑥) ⊆ (𝐴 ∖ 𝑦) ∨ (𝐴 ∖ 𝑦) ⊆ (𝐴 ∖ 𝑥)))) |
| 12 | | velpw 4605 |
. . . . . . . . . . 11
⊢ (𝑥 ∈ 𝒫 𝐴 ↔ 𝑥 ⊆ 𝐴) |
| 13 | | dfss4 4269 |
. . . . . . . . . . 11
⊢ (𝑥 ⊆ 𝐴 ↔ (𝐴 ∖ (𝐴 ∖ 𝑥)) = 𝑥) |
| 14 | 12, 13 | bitri 275 |
. . . . . . . . . 10
⊢ (𝑥 ∈ 𝒫 𝐴 ↔ (𝐴 ∖ (𝐴 ∖ 𝑥)) = 𝑥) |
| 15 | | velpw 4605 |
. . . . . . . . . . 11
⊢ (𝑦 ∈ 𝒫 𝐴 ↔ 𝑦 ⊆ 𝐴) |
| 16 | | dfss4 4269 |
. . . . . . . . . . 11
⊢ (𝑦 ⊆ 𝐴 ↔ (𝐴 ∖ (𝐴 ∖ 𝑦)) = 𝑦) |
| 17 | 15, 16 | bitri 275 |
. . . . . . . . . 10
⊢ (𝑦 ∈ 𝒫 𝐴 ↔ (𝐴 ∖ (𝐴 ∖ 𝑦)) = 𝑦) |
| 18 | | sscon 4143 |
. . . . . . . . . . . 12
⊢ ((𝐴 ∖ 𝑦) ⊆ (𝐴 ∖ 𝑥) → (𝐴 ∖ (𝐴 ∖ 𝑥)) ⊆ (𝐴 ∖ (𝐴 ∖ 𝑦))) |
| 19 | | sseq12 4011 |
. . . . . . . . . . . 12
⊢ (((𝐴 ∖ (𝐴 ∖ 𝑥)) = 𝑥 ∧ (𝐴 ∖ (𝐴 ∖ 𝑦)) = 𝑦) → ((𝐴 ∖ (𝐴 ∖ 𝑥)) ⊆ (𝐴 ∖ (𝐴 ∖ 𝑦)) ↔ 𝑥 ⊆ 𝑦)) |
| 20 | 18, 19 | imbitrid 244 |
. . . . . . . . . . 11
⊢ (((𝐴 ∖ (𝐴 ∖ 𝑥)) = 𝑥 ∧ (𝐴 ∖ (𝐴 ∖ 𝑦)) = 𝑦) → ((𝐴 ∖ 𝑦) ⊆ (𝐴 ∖ 𝑥) → 𝑥 ⊆ 𝑦)) |
| 21 | | sscon 4143 |
. . . . . . . . . . . 12
⊢ ((𝐴 ∖ 𝑥) ⊆ (𝐴 ∖ 𝑦) → (𝐴 ∖ (𝐴 ∖ 𝑦)) ⊆ (𝐴 ∖ (𝐴 ∖ 𝑥))) |
| 22 | | sseq12 4011 |
. . . . . . . . . . . . 13
⊢ (((𝐴 ∖ (𝐴 ∖ 𝑦)) = 𝑦 ∧ (𝐴 ∖ (𝐴 ∖ 𝑥)) = 𝑥) → ((𝐴 ∖ (𝐴 ∖ 𝑦)) ⊆ (𝐴 ∖ (𝐴 ∖ 𝑥)) ↔ 𝑦 ⊆ 𝑥)) |
| 23 | 22 | ancoms 458 |
. . . . . . . . . . . 12
⊢ (((𝐴 ∖ (𝐴 ∖ 𝑥)) = 𝑥 ∧ (𝐴 ∖ (𝐴 ∖ 𝑦)) = 𝑦) → ((𝐴 ∖ (𝐴 ∖ 𝑦)) ⊆ (𝐴 ∖ (𝐴 ∖ 𝑥)) ↔ 𝑦 ⊆ 𝑥)) |
| 24 | 21, 23 | imbitrid 244 |
. . . . . . . . . . 11
⊢ (((𝐴 ∖ (𝐴 ∖ 𝑥)) = 𝑥 ∧ (𝐴 ∖ (𝐴 ∖ 𝑦)) = 𝑦) → ((𝐴 ∖ 𝑥) ⊆ (𝐴 ∖ 𝑦) → 𝑦 ⊆ 𝑥)) |
| 25 | 20, 24 | orim12d 967 |
. . . . . . . . . 10
⊢ (((𝐴 ∖ (𝐴 ∖ 𝑥)) = 𝑥 ∧ (𝐴 ∖ (𝐴 ∖ 𝑦)) = 𝑦) → (((𝐴 ∖ 𝑦) ⊆ (𝐴 ∖ 𝑥) ∨ (𝐴 ∖ 𝑥) ⊆ (𝐴 ∖ 𝑦)) → (𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥))) |
| 26 | 14, 17, 25 | syl2anb 598 |
. . . . . . . . 9
⊢ ((𝑥 ∈ 𝒫 𝐴 ∧ 𝑦 ∈ 𝒫 𝐴) → (((𝐴 ∖ 𝑦) ⊆ (𝐴 ∖ 𝑥) ∨ (𝐴 ∖ 𝑥) ⊆ (𝐴 ∖ 𝑦)) → (𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥))) |
| 27 | 26 | com12 32 |
. . . . . . . 8
⊢ (((𝐴 ∖ 𝑦) ⊆ (𝐴 ∖ 𝑥) ∨ (𝐴 ∖ 𝑥) ⊆ (𝐴 ∖ 𝑦)) → ((𝑥 ∈ 𝒫 𝐴 ∧ 𝑦 ∈ 𝒫 𝐴) → (𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥))) |
| 28 | 27 | orcoms 873 |
. . . . . . 7
⊢ (((𝐴 ∖ 𝑥) ⊆ (𝐴 ∖ 𝑦) ∨ (𝐴 ∖ 𝑦) ⊆ (𝐴 ∖ 𝑥)) → ((𝑥 ∈ 𝒫 𝐴 ∧ 𝑦 ∈ 𝒫 𝐴) → (𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥))) |
| 29 | 11, 28 | syl6 35 |
. . . . . 6
⊢ (((𝐴 ∖ 𝑥) ∈ 𝑌 ∧ (𝐴 ∖ 𝑦) ∈ 𝑌) → ( [⊊] Or 𝑌 → ((𝑥 ∈ 𝒫 𝐴 ∧ 𝑦 ∈ 𝒫 𝐴) → (𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥)))) |
| 30 | 29 | com3l 89 |
. . . . 5
⊢ (
[⊊] Or 𝑌
→ ((𝑥 ∈ 𝒫
𝐴 ∧ 𝑦 ∈ 𝒫 𝐴) → (((𝐴 ∖ 𝑥) ∈ 𝑌 ∧ (𝐴 ∖ 𝑦) ∈ 𝑌) → (𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥)))) |
| 31 | 30 | impd 410 |
. . . 4
⊢ (
[⊊] Or 𝑌
→ (((𝑥 ∈
𝒫 𝐴 ∧ 𝑦 ∈ 𝒫 𝐴) ∧ ((𝐴 ∖ 𝑥) ∈ 𝑌 ∧ (𝐴 ∖ 𝑦) ∈ 𝑌)) → (𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥))) |
| 32 | 9, 31 | syl5 34 |
. . 3
⊢ (
[⊊] Or 𝑌
→ ((𝑥 ∈ {𝑢 ∈ 𝒫 𝐴 ∣ (𝐴 ∖ 𝑢) ∈ 𝑌} ∧ 𝑦 ∈ {𝑢 ∈ 𝒫 𝐴 ∣ (𝐴 ∖ 𝑢) ∈ 𝑌}) → (𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥))) |
| 33 | 32 | ralrimivv 3200 |
. 2
⊢ (
[⊊] Or 𝑌
→ ∀𝑥 ∈
{𝑢 ∈ 𝒫 𝐴 ∣ (𝐴 ∖ 𝑢) ∈ 𝑌}∀𝑦 ∈ {𝑢 ∈ 𝒫 𝐴 ∣ (𝐴 ∖ 𝑢) ∈ 𝑌} (𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥)) |
| 34 | | sorpss 7748 |
. 2
⊢ (
[⊊] Or {𝑢
∈ 𝒫 𝐴 ∣
(𝐴 ∖ 𝑢) ∈ 𝑌} ↔ ∀𝑥 ∈ {𝑢 ∈ 𝒫 𝐴 ∣ (𝐴 ∖ 𝑢) ∈ 𝑌}∀𝑦 ∈ {𝑢 ∈ 𝒫 𝐴 ∣ (𝐴 ∖ 𝑢) ∈ 𝑌} (𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥)) |
| 35 | 33, 34 | sylibr 234 |
1
⊢ (
[⊊] Or 𝑌
→ [⊊] Or {𝑢 ∈ 𝒫 𝐴 ∣ (𝐴 ∖ 𝑢) ∈ 𝑌}) |