| Step | Hyp | Ref
| Expression |
| 1 | | biimp 215 |
. . . . . 6
⊢ (((𝑢 × {𝑥}) ⊆ 𝑀 ↔ (𝑢 × {𝑡}) ⊆ 𝑀) → ((𝑢 × {𝑥}) ⊆ 𝑀 → (𝑢 × {𝑡}) ⊆ 𝑀)) |
| 2 | | iitop 24829 |
. . . . . . . . . . 11
⊢ II ∈
Top |
| 3 | | iiuni 24830 |
. . . . . . . . . . . 12
⊢ (0[,]1) =
∪ II |
| 4 | 3 | neii1 23049 |
. . . . . . . . . . 11
⊢ ((II
∈ Top ∧ 𝑢 ∈
((nei‘II)‘{𝑦}))
→ 𝑢 ⊆
(0[,]1)) |
| 5 | 2, 4 | mpan 690 |
. . . . . . . . . 10
⊢ (𝑢 ∈
((nei‘II)‘{𝑦})
→ 𝑢 ⊆
(0[,]1)) |
| 6 | 5 | adantl 481 |
. . . . . . . . 9
⊢
((((0[,]1) × {𝑥}) ⊆ 𝑀 ∧ 𝑢 ∈ ((nei‘II)‘{𝑦})) → 𝑢 ⊆ (0[,]1)) |
| 7 | | xpss1 5678 |
. . . . . . . . 9
⊢ (𝑢 ⊆ (0[,]1) → (𝑢 × {𝑥}) ⊆ ((0[,]1) × {𝑥})) |
| 8 | 6, 7 | syl 17 |
. . . . . . . 8
⊢
((((0[,]1) × {𝑥}) ⊆ 𝑀 ∧ 𝑢 ∈ ((nei‘II)‘{𝑦})) → (𝑢 × {𝑥}) ⊆ ((0[,]1) × {𝑥})) |
| 9 | | simpl 482 |
. . . . . . . 8
⊢
((((0[,]1) × {𝑥}) ⊆ 𝑀 ∧ 𝑢 ∈ ((nei‘II)‘{𝑦})) → ((0[,]1) ×
{𝑥}) ⊆ 𝑀) |
| 10 | 8, 9 | sstrd 3974 |
. . . . . . 7
⊢
((((0[,]1) × {𝑥}) ⊆ 𝑀 ∧ 𝑢 ∈ ((nei‘II)‘{𝑦})) → (𝑢 × {𝑥}) ⊆ 𝑀) |
| 11 | | ssnei 23053 |
. . . . . . . . . . . 12
⊢ ((II
∈ Top ∧ 𝑢 ∈
((nei‘II)‘{𝑦}))
→ {𝑦} ⊆ 𝑢) |
| 12 | 2, 11 | mpan 690 |
. . . . . . . . . . 11
⊢ (𝑢 ∈
((nei‘II)‘{𝑦})
→ {𝑦} ⊆ 𝑢) |
| 13 | 12 | adantl 481 |
. . . . . . . . . 10
⊢
((((0[,]1) × {𝑥}) ⊆ 𝑀 ∧ 𝑢 ∈ ((nei‘II)‘{𝑦})) → {𝑦} ⊆ 𝑢) |
| 14 | | vex 3468 |
. . . . . . . . . . 11
⊢ 𝑦 ∈ V |
| 15 | 14 | snss 4766 |
. . . . . . . . . 10
⊢ (𝑦 ∈ 𝑢 ↔ {𝑦} ⊆ 𝑢) |
| 16 | 13, 15 | sylibr 234 |
. . . . . . . . 9
⊢
((((0[,]1) × {𝑥}) ⊆ 𝑀 ∧ 𝑢 ∈ ((nei‘II)‘{𝑦})) → 𝑦 ∈ 𝑢) |
| 17 | | vsnid 4644 |
. . . . . . . . 9
⊢ 𝑡 ∈ {𝑡} |
| 18 | | opelxpi 5696 |
. . . . . . . . 9
⊢ ((𝑦 ∈ 𝑢 ∧ 𝑡 ∈ {𝑡}) → 〈𝑦, 𝑡〉 ∈ (𝑢 × {𝑡})) |
| 19 | 16, 17, 18 | sylancl 586 |
. . . . . . . 8
⊢
((((0[,]1) × {𝑥}) ⊆ 𝑀 ∧ 𝑢 ∈ ((nei‘II)‘{𝑦})) → 〈𝑦, 𝑡〉 ∈ (𝑢 × {𝑡})) |
| 20 | | ssel 3957 |
. . . . . . . 8
⊢ ((𝑢 × {𝑡}) ⊆ 𝑀 → (〈𝑦, 𝑡〉 ∈ (𝑢 × {𝑡}) → 〈𝑦, 𝑡〉 ∈ 𝑀)) |
| 21 | 19, 20 | syl5com 31 |
. . . . . . 7
⊢
((((0[,]1) × {𝑥}) ⊆ 𝑀 ∧ 𝑢 ∈ ((nei‘II)‘{𝑦})) → ((𝑢 × {𝑡}) ⊆ 𝑀 → 〈𝑦, 𝑡〉 ∈ 𝑀)) |
| 22 | 10, 21 | embantd 59 |
. . . . . 6
⊢
((((0[,]1) × {𝑥}) ⊆ 𝑀 ∧ 𝑢 ∈ ((nei‘II)‘{𝑦})) → (((𝑢 × {𝑥}) ⊆ 𝑀 → (𝑢 × {𝑡}) ⊆ 𝑀) → 〈𝑦, 𝑡〉 ∈ 𝑀)) |
| 23 | 1, 22 | syl5 34 |
. . . . 5
⊢
((((0[,]1) × {𝑥}) ⊆ 𝑀 ∧ 𝑢 ∈ ((nei‘II)‘{𝑦})) → (((𝑢 × {𝑥}) ⊆ 𝑀 ↔ (𝑢 × {𝑡}) ⊆ 𝑀) → 〈𝑦, 𝑡〉 ∈ 𝑀)) |
| 24 | 23 | rexlimdva 3142 |
. . . 4
⊢ (((0[,]1)
× {𝑥}) ⊆ 𝑀 → (∃𝑢 ∈
((nei‘II)‘{𝑦})((𝑢 × {𝑥}) ⊆ 𝑀 ↔ (𝑢 × {𝑡}) ⊆ 𝑀) → 〈𝑦, 𝑡〉 ∈ 𝑀)) |
| 25 | 24 | ralimdv 3155 |
. . 3
⊢ (((0[,]1)
× {𝑥}) ⊆ 𝑀 → (∀𝑦 ∈ (0[,]1)∃𝑢 ∈
((nei‘II)‘{𝑦})((𝑢 × {𝑥}) ⊆ 𝑀 ↔ (𝑢 × {𝑡}) ⊆ 𝑀) → ∀𝑦 ∈ (0[,]1)〈𝑦, 𝑡〉 ∈ 𝑀)) |
| 26 | 25 | com12 32 |
. 2
⊢
(∀𝑦 ∈
(0[,]1)∃𝑢 ∈
((nei‘II)‘{𝑦})((𝑢 × {𝑥}) ⊆ 𝑀 ↔ (𝑢 × {𝑡}) ⊆ 𝑀) → (((0[,]1) × {𝑥}) ⊆ 𝑀 → ∀𝑦 ∈ (0[,]1)〈𝑦, 𝑡〉 ∈ 𝑀)) |
| 27 | | dfss3 3952 |
. . 3
⊢ (((0[,]1)
× {𝑡}) ⊆ 𝑀 ↔ ∀𝑧 ∈ ((0[,]1) × {𝑡})𝑧 ∈ 𝑀) |
| 28 | | eleq1 2823 |
. . . 4
⊢ (𝑧 = 〈𝑦, 𝑢〉 → (𝑧 ∈ 𝑀 ↔ 〈𝑦, 𝑢〉 ∈ 𝑀)) |
| 29 | 28 | ralxp 5826 |
. . 3
⊢
(∀𝑧 ∈
((0[,]1) × {𝑡})𝑧 ∈ 𝑀 ↔ ∀𝑦 ∈ (0[,]1)∀𝑢 ∈ {𝑡}〈𝑦, 𝑢〉 ∈ 𝑀) |
| 30 | | vex 3468 |
. . . . 5
⊢ 𝑡 ∈ V |
| 31 | | opeq2 4855 |
. . . . . 6
⊢ (𝑢 = 𝑡 → 〈𝑦, 𝑢〉 = 〈𝑦, 𝑡〉) |
| 32 | 31 | eleq1d 2820 |
. . . . 5
⊢ (𝑢 = 𝑡 → (〈𝑦, 𝑢〉 ∈ 𝑀 ↔ 〈𝑦, 𝑡〉 ∈ 𝑀)) |
| 33 | 30, 32 | ralsn 4662 |
. . . 4
⊢
(∀𝑢 ∈
{𝑡}〈𝑦, 𝑢〉 ∈ 𝑀 ↔ 〈𝑦, 𝑡〉 ∈ 𝑀) |
| 34 | 33 | ralbii 3083 |
. . 3
⊢
(∀𝑦 ∈
(0[,]1)∀𝑢 ∈
{𝑡}〈𝑦, 𝑢〉 ∈ 𝑀 ↔ ∀𝑦 ∈ (0[,]1)〈𝑦, 𝑡〉 ∈ 𝑀) |
| 35 | 27, 29, 34 | 3bitri 297 |
. 2
⊢ (((0[,]1)
× {𝑡}) ⊆ 𝑀 ↔ ∀𝑦 ∈ (0[,]1)〈𝑦, 𝑡〉 ∈ 𝑀) |
| 36 | 26, 35 | imbitrrdi 252 |
1
⊢
(∀𝑦 ∈
(0[,]1)∃𝑢 ∈
((nei‘II)‘{𝑦})((𝑢 × {𝑥}) ⊆ 𝑀 ↔ (𝑢 × {𝑡}) ⊆ 𝑀) → (((0[,]1) × {𝑥}) ⊆ 𝑀 → ((0[,]1) × {𝑡}) ⊆ 𝑀)) |