Step | Hyp | Ref
| Expression |
1 | | breq1 3767 |
. . . . 5
⊢ (𝑏 = 𝑦 → (𝑏 ≤ 𝑎 ↔ 𝑦 ≤ 𝑎)) |
2 | 1 | cbvralv 2533 |
. . . 4
⊢
(∀𝑏 ∈
𝐴 𝑏 ≤ 𝑎 ↔ ∀𝑦 ∈ 𝐴 𝑦 ≤ 𝑎) |
3 | 2 | rexbii 2331 |
. . 3
⊢
(∃𝑎 ∈
ℝ ∀𝑏 ∈
𝐴 𝑏 ≤ 𝑎 ↔ ∃𝑎 ∈ ℝ ∀𝑦 ∈ 𝐴 𝑦 ≤ 𝑎) |
4 | | breq2 3768 |
. . . . 5
⊢ (𝑎 = 𝑥 → (𝑦 ≤ 𝑎 ↔ 𝑦 ≤ 𝑥)) |
5 | 4 | ralbidv 2326 |
. . . 4
⊢ (𝑎 = 𝑥 → (∀𝑦 ∈ 𝐴 𝑦 ≤ 𝑎 ↔ ∀𝑦 ∈ 𝐴 𝑦 ≤ 𝑥)) |
6 | 5 | cbvrexv 2534 |
. . 3
⊢
(∃𝑎 ∈
ℝ ∀𝑦 ∈
𝐴 𝑦 ≤ 𝑎 ↔ ∃𝑥 ∈ ℝ ∀𝑦 ∈ 𝐴 𝑦 ≤ 𝑥) |
7 | 3, 6 | bitri 173 |
. 2
⊢
(∃𝑎 ∈
ℝ ∀𝑏 ∈
𝐴 𝑏 ≤ 𝑎 ↔ ∃𝑥 ∈ ℝ ∀𝑦 ∈ 𝐴 𝑦 ≤ 𝑥) |
8 | | renegcl 7272 |
. . . 4
⊢ (𝑎 ∈ ℝ → -𝑎 ∈
ℝ) |
9 | | elrabi 2695 |
. . . . . . . . 9
⊢ (𝑦 ∈ {𝑧 ∈ ℝ ∣ -𝑧 ∈ 𝐴} → 𝑦 ∈ ℝ) |
10 | | negeq 7204 |
. . . . . . . . . . . 12
⊢ (𝑧 = 𝑦 → -𝑧 = -𝑦) |
11 | 10 | eleq1d 2106 |
. . . . . . . . . . 11
⊢ (𝑧 = 𝑦 → (-𝑧 ∈ 𝐴 ↔ -𝑦 ∈ 𝐴)) |
12 | 11 | elrab3 2699 |
. . . . . . . . . 10
⊢ (𝑦 ∈ ℝ → (𝑦 ∈ {𝑧 ∈ ℝ ∣ -𝑧 ∈ 𝐴} ↔ -𝑦 ∈ 𝐴)) |
13 | 12 | biimpd 132 |
. . . . . . . . 9
⊢ (𝑦 ∈ ℝ → (𝑦 ∈ {𝑧 ∈ ℝ ∣ -𝑧 ∈ 𝐴} → -𝑦 ∈ 𝐴)) |
14 | 9, 13 | mpcom 32 |
. . . . . . . 8
⊢ (𝑦 ∈ {𝑧 ∈ ℝ ∣ -𝑧 ∈ 𝐴} → -𝑦 ∈ 𝐴) |
15 | | breq1 3767 |
. . . . . . . . 9
⊢ (𝑏 = -𝑦 → (𝑏 ≤ 𝑎 ↔ -𝑦 ≤ 𝑎)) |
16 | 15 | rspcv 2652 |
. . . . . . . 8
⊢ (-𝑦 ∈ 𝐴 → (∀𝑏 ∈ 𝐴 𝑏 ≤ 𝑎 → -𝑦 ≤ 𝑎)) |
17 | 14, 16 | syl 14 |
. . . . . . 7
⊢ (𝑦 ∈ {𝑧 ∈ ℝ ∣ -𝑧 ∈ 𝐴} → (∀𝑏 ∈ 𝐴 𝑏 ≤ 𝑎 → -𝑦 ≤ 𝑎)) |
18 | 17 | adantl 262 |
. . . . . 6
⊢ ((𝑎 ∈ ℝ ∧ 𝑦 ∈ {𝑧 ∈ ℝ ∣ -𝑧 ∈ 𝐴}) → (∀𝑏 ∈ 𝐴 𝑏 ≤ 𝑎 → -𝑦 ≤ 𝑎)) |
19 | | lenegcon1 7461 |
. . . . . . 7
⊢ ((𝑎 ∈ ℝ ∧ 𝑦 ∈ ℝ) → (-𝑎 ≤ 𝑦 ↔ -𝑦 ≤ 𝑎)) |
20 | 9, 19 | sylan2 270 |
. . . . . 6
⊢ ((𝑎 ∈ ℝ ∧ 𝑦 ∈ {𝑧 ∈ ℝ ∣ -𝑧 ∈ 𝐴}) → (-𝑎 ≤ 𝑦 ↔ -𝑦 ≤ 𝑎)) |
21 | 18, 20 | sylibrd 158 |
. . . . 5
⊢ ((𝑎 ∈ ℝ ∧ 𝑦 ∈ {𝑧 ∈ ℝ ∣ -𝑧 ∈ 𝐴}) → (∀𝑏 ∈ 𝐴 𝑏 ≤ 𝑎 → -𝑎 ≤ 𝑦)) |
22 | 21 | ralrimdva 2399 |
. . . 4
⊢ (𝑎 ∈ ℝ →
(∀𝑏 ∈ 𝐴 𝑏 ≤ 𝑎 → ∀𝑦 ∈ {𝑧 ∈ ℝ ∣ -𝑧 ∈ 𝐴}-𝑎 ≤ 𝑦)) |
23 | | breq1 3767 |
. . . . . 6
⊢ (𝑥 = -𝑎 → (𝑥 ≤ 𝑦 ↔ -𝑎 ≤ 𝑦)) |
24 | 23 | ralbidv 2326 |
. . . . 5
⊢ (𝑥 = -𝑎 → (∀𝑦 ∈ {𝑧 ∈ ℝ ∣ -𝑧 ∈ 𝐴}𝑥 ≤ 𝑦 ↔ ∀𝑦 ∈ {𝑧 ∈ ℝ ∣ -𝑧 ∈ 𝐴}-𝑎 ≤ 𝑦)) |
25 | 24 | rspcev 2656 |
. . . 4
⊢ ((-𝑎 ∈ ℝ ∧
∀𝑦 ∈ {𝑧 ∈ ℝ ∣ -𝑧 ∈ 𝐴}-𝑎 ≤ 𝑦) → ∃𝑥 ∈ ℝ ∀𝑦 ∈ {𝑧 ∈ ℝ ∣ -𝑧 ∈ 𝐴}𝑥 ≤ 𝑦) |
26 | 8, 22, 25 | syl6an 1323 |
. . 3
⊢ (𝑎 ∈ ℝ →
(∀𝑏 ∈ 𝐴 𝑏 ≤ 𝑎 → ∃𝑥 ∈ ℝ ∀𝑦 ∈ {𝑧 ∈ ℝ ∣ -𝑧 ∈ 𝐴}𝑥 ≤ 𝑦)) |
27 | 26 | rexlimiv 2427 |
. 2
⊢
(∃𝑎 ∈
ℝ ∀𝑏 ∈
𝐴 𝑏 ≤ 𝑎 → ∃𝑥 ∈ ℝ ∀𝑦 ∈ {𝑧 ∈ ℝ ∣ -𝑧 ∈ 𝐴}𝑥 ≤ 𝑦) |
28 | 7, 27 | sylbir 125 |
1
⊢
(∃𝑥 ∈
ℝ ∀𝑦 ∈
𝐴 𝑦 ≤ 𝑥 → ∃𝑥 ∈ ℝ ∀𝑦 ∈ {𝑧 ∈ ℝ ∣ -𝑧 ∈ 𝐴}𝑥 ≤ 𝑦) |