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Theorem infm3 10861
 Description: The completeness axiom for reals in terms of infimum: a nonempty, bounded-below set of reals has an infimum. (This theorem is the dual of sup3 10859.) (Contributed by NM, 14-Jun-2005.)
Assertion
Ref Expression
infm3 ((𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ∧ ∃𝑥 ∈ ℝ ∀𝑦𝐴 𝑥𝑦) → ∃𝑥 ∈ ℝ (∀𝑦𝐴 ¬ 𝑦 < 𝑥 ∧ ∀𝑦 ∈ ℝ (𝑥 < 𝑦 → ∃𝑧𝐴 𝑧 < 𝑦)))
Distinct variable group:   𝑥,𝑦,𝑧,𝐴

Proof of Theorem infm3
Dummy variables 𝑤 𝑣 𝑢 𝑡 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 ssel 3562 . . . . . . . . 9 (𝐴 ⊆ ℝ → (𝑣𝐴𝑣 ∈ ℝ))
21pm4.71rd 665 . . . . . . . 8 (𝐴 ⊆ ℝ → (𝑣𝐴 ↔ (𝑣 ∈ ℝ ∧ 𝑣𝐴)))
32exbidv 1837 . . . . . . 7 (𝐴 ⊆ ℝ → (∃𝑣 𝑣𝐴 ↔ ∃𝑣(𝑣 ∈ ℝ ∧ 𝑣𝐴)))
4 df-rex 2902 . . . . . . . 8 (∃𝑣 ∈ ℝ 𝑣𝐴 ↔ ∃𝑣(𝑣 ∈ ℝ ∧ 𝑣𝐴))
5 renegcl 10223 . . . . . . . . 9 (𝑤 ∈ ℝ → -𝑤 ∈ ℝ)
6 infm3lem 10860 . . . . . . . . 9 (𝑣 ∈ ℝ → ∃𝑤 ∈ ℝ 𝑣 = -𝑤)
7 eleq1 2676 . . . . . . . . 9 (𝑣 = -𝑤 → (𝑣𝐴 ↔ -𝑤𝐴))
85, 6, 7rexxfr 4814 . . . . . . . 8 (∃𝑣 ∈ ℝ 𝑣𝐴 ↔ ∃𝑤 ∈ ℝ -𝑤𝐴)
94, 8bitr3i 265 . . . . . . 7 (∃𝑣(𝑣 ∈ ℝ ∧ 𝑣𝐴) ↔ ∃𝑤 ∈ ℝ -𝑤𝐴)
103, 9syl6bb 275 . . . . . 6 (𝐴 ⊆ ℝ → (∃𝑣 𝑣𝐴 ↔ ∃𝑤 ∈ ℝ -𝑤𝐴))
11 n0 3890 . . . . . 6 (𝐴 ≠ ∅ ↔ ∃𝑣 𝑣𝐴)
12 rabn0 3912 . . . . . 6 ({𝑤 ∈ ℝ ∣ -𝑤𝐴} ≠ ∅ ↔ ∃𝑤 ∈ ℝ -𝑤𝐴)
1310, 11, 123bitr4g 302 . . . . 5 (𝐴 ⊆ ℝ → (𝐴 ≠ ∅ ↔ {𝑤 ∈ ℝ ∣ -𝑤𝐴} ≠ ∅))
14 ssel 3562 . . . . . . . . . . . 12 (𝐴 ⊆ ℝ → (𝑦𝐴𝑦 ∈ ℝ))
1514pm4.71rd 665 . . . . . . . . . . 11 (𝐴 ⊆ ℝ → (𝑦𝐴 ↔ (𝑦 ∈ ℝ ∧ 𝑦𝐴)))
1615imbi1d 330 . . . . . . . . . 10 (𝐴 ⊆ ℝ → ((𝑦𝐴𝑥𝑦) ↔ ((𝑦 ∈ ℝ ∧ 𝑦𝐴) → 𝑥𝑦)))
17 impexp 461 . . . . . . . . . 10 (((𝑦 ∈ ℝ ∧ 𝑦𝐴) → 𝑥𝑦) ↔ (𝑦 ∈ ℝ → (𝑦𝐴𝑥𝑦)))
1816, 17syl6bb 275 . . . . . . . . 9 (𝐴 ⊆ ℝ → ((𝑦𝐴𝑥𝑦) ↔ (𝑦 ∈ ℝ → (𝑦𝐴𝑥𝑦))))
1918albidv 1836 . . . . . . . 8 (𝐴 ⊆ ℝ → (∀𝑦(𝑦𝐴𝑥𝑦) ↔ ∀𝑦(𝑦 ∈ ℝ → (𝑦𝐴𝑥𝑦))))
20 df-ral 2901 . . . . . . . 8 (∀𝑦𝐴 𝑥𝑦 ↔ ∀𝑦(𝑦𝐴𝑥𝑦))
21 renegcl 10223 . . . . . . . . . 10 (𝑣 ∈ ℝ → -𝑣 ∈ ℝ)
22 infm3lem 10860 . . . . . . . . . 10 (𝑦 ∈ ℝ → ∃𝑣 ∈ ℝ 𝑦 = -𝑣)
23 eleq1 2676 . . . . . . . . . . 11 (𝑦 = -𝑣 → (𝑦𝐴 ↔ -𝑣𝐴))
24 breq2 4587 . . . . . . . . . . 11 (𝑦 = -𝑣 → (𝑥𝑦𝑥 ≤ -𝑣))
2523, 24imbi12d 333 . . . . . . . . . 10 (𝑦 = -𝑣 → ((𝑦𝐴𝑥𝑦) ↔ (-𝑣𝐴𝑥 ≤ -𝑣)))
2621, 22, 25ralxfr 4812 . . . . . . . . 9 (∀𝑦 ∈ ℝ (𝑦𝐴𝑥𝑦) ↔ ∀𝑣 ∈ ℝ (-𝑣𝐴𝑥 ≤ -𝑣))
27 df-ral 2901 . . . . . . . . 9 (∀𝑦 ∈ ℝ (𝑦𝐴𝑥𝑦) ↔ ∀𝑦(𝑦 ∈ ℝ → (𝑦𝐴𝑥𝑦)))
2826, 27bitr3i 265 . . . . . . . 8 (∀𝑣 ∈ ℝ (-𝑣𝐴𝑥 ≤ -𝑣) ↔ ∀𝑦(𝑦 ∈ ℝ → (𝑦𝐴𝑥𝑦)))
2919, 20, 283bitr4g 302 . . . . . . 7 (𝐴 ⊆ ℝ → (∀𝑦𝐴 𝑥𝑦 ↔ ∀𝑣 ∈ ℝ (-𝑣𝐴𝑥 ≤ -𝑣)))
3029rexbidv 3034 . . . . . 6 (𝐴 ⊆ ℝ → (∃𝑥 ∈ ℝ ∀𝑦𝐴 𝑥𝑦 ↔ ∃𝑥 ∈ ℝ ∀𝑣 ∈ ℝ (-𝑣𝐴𝑥 ≤ -𝑣)))
31 renegcl 10223 . . . . . . . 8 (𝑢 ∈ ℝ → -𝑢 ∈ ℝ)
32 infm3lem 10860 . . . . . . . 8 (𝑥 ∈ ℝ → ∃𝑢 ∈ ℝ 𝑥 = -𝑢)
33 breq1 4586 . . . . . . . . . 10 (𝑥 = -𝑢 → (𝑥 ≤ -𝑣 ↔ -𝑢 ≤ -𝑣))
3433imbi2d 329 . . . . . . . . 9 (𝑥 = -𝑢 → ((-𝑣𝐴𝑥 ≤ -𝑣) ↔ (-𝑣𝐴 → -𝑢 ≤ -𝑣)))
3534ralbidv 2969 . . . . . . . 8 (𝑥 = -𝑢 → (∀𝑣 ∈ ℝ (-𝑣𝐴𝑥 ≤ -𝑣) ↔ ∀𝑣 ∈ ℝ (-𝑣𝐴 → -𝑢 ≤ -𝑣)))
3631, 32, 35rexxfr 4814 . . . . . . 7 (∃𝑥 ∈ ℝ ∀𝑣 ∈ ℝ (-𝑣𝐴𝑥 ≤ -𝑣) ↔ ∃𝑢 ∈ ℝ ∀𝑣 ∈ ℝ (-𝑣𝐴 → -𝑢 ≤ -𝑣))
37 negeq 10152 . . . . . . . . . . . . . . 15 (𝑤 = 𝑣 → -𝑤 = -𝑣)
3837eleq1d 2672 . . . . . . . . . . . . . 14 (𝑤 = 𝑣 → (-𝑤𝐴 ↔ -𝑣𝐴))
3938elrab 3331 . . . . . . . . . . . . 13 (𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} ↔ (𝑣 ∈ ℝ ∧ -𝑣𝐴))
4039imbi1i 338 . . . . . . . . . . . 12 ((𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} → 𝑣𝑢) ↔ ((𝑣 ∈ ℝ ∧ -𝑣𝐴) → 𝑣𝑢))
41 impexp 461 . . . . . . . . . . . 12 (((𝑣 ∈ ℝ ∧ -𝑣𝐴) → 𝑣𝑢) ↔ (𝑣 ∈ ℝ → (-𝑣𝐴𝑣𝑢)))
4240, 41bitri 263 . . . . . . . . . . 11 ((𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} → 𝑣𝑢) ↔ (𝑣 ∈ ℝ → (-𝑣𝐴𝑣𝑢)))
4342albii 1737 . . . . . . . . . 10 (∀𝑣(𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} → 𝑣𝑢) ↔ ∀𝑣(𝑣 ∈ ℝ → (-𝑣𝐴𝑣𝑢)))
44 df-ral 2901 . . . . . . . . . 10 (∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣𝑢 ↔ ∀𝑣(𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} → 𝑣𝑢))
45 df-ral 2901 . . . . . . . . . 10 (∀𝑣 ∈ ℝ (-𝑣𝐴𝑣𝑢) ↔ ∀𝑣(𝑣 ∈ ℝ → (-𝑣𝐴𝑣𝑢)))
4643, 44, 453bitr4ri 292 . . . . . . . . 9 (∀𝑣 ∈ ℝ (-𝑣𝐴𝑣𝑢) ↔ ∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣𝑢)
47 leneg 10410 . . . . . . . . . . . 12 ((𝑣 ∈ ℝ ∧ 𝑢 ∈ ℝ) → (𝑣𝑢 ↔ -𝑢 ≤ -𝑣))
4847ancoms 468 . . . . . . . . . . 11 ((𝑢 ∈ ℝ ∧ 𝑣 ∈ ℝ) → (𝑣𝑢 ↔ -𝑢 ≤ -𝑣))
4948imbi2d 329 . . . . . . . . . 10 ((𝑢 ∈ ℝ ∧ 𝑣 ∈ ℝ) → ((-𝑣𝐴𝑣𝑢) ↔ (-𝑣𝐴 → -𝑢 ≤ -𝑣)))
5049ralbidva 2968 . . . . . . . . 9 (𝑢 ∈ ℝ → (∀𝑣 ∈ ℝ (-𝑣𝐴𝑣𝑢) ↔ ∀𝑣 ∈ ℝ (-𝑣𝐴 → -𝑢 ≤ -𝑣)))
5146, 50syl5bbr 273 . . . . . . . 8 (𝑢 ∈ ℝ → (∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣𝑢 ↔ ∀𝑣 ∈ ℝ (-𝑣𝐴 → -𝑢 ≤ -𝑣)))
5251rexbiia 3022 . . . . . . 7 (∃𝑢 ∈ ℝ ∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣𝑢 ↔ ∃𝑢 ∈ ℝ ∀𝑣 ∈ ℝ (-𝑣𝐴 → -𝑢 ≤ -𝑣))
5336, 52bitr4i 266 . . . . . 6 (∃𝑥 ∈ ℝ ∀𝑣 ∈ ℝ (-𝑣𝐴𝑥 ≤ -𝑣) ↔ ∃𝑢 ∈ ℝ ∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣𝑢)
5430, 53syl6bb 275 . . . . 5 (𝐴 ⊆ ℝ → (∃𝑥 ∈ ℝ ∀𝑦𝐴 𝑥𝑦 ↔ ∃𝑢 ∈ ℝ ∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣𝑢))
5513, 54anbi12d 743 . . . 4 (𝐴 ⊆ ℝ → ((𝐴 ≠ ∅ ∧ ∃𝑥 ∈ ℝ ∀𝑦𝐴 𝑥𝑦) ↔ ({𝑤 ∈ ℝ ∣ -𝑤𝐴} ≠ ∅ ∧ ∃𝑢 ∈ ℝ ∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣𝑢)))
56 ssrab2 3650 . . . . 5 {𝑤 ∈ ℝ ∣ -𝑤𝐴} ⊆ ℝ
57 sup3 10859 . . . . 5 (({𝑤 ∈ ℝ ∣ -𝑤𝐴} ⊆ ℝ ∧ {𝑤 ∈ ℝ ∣ -𝑤𝐴} ≠ ∅ ∧ ∃𝑢 ∈ ℝ ∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣𝑢) → ∃𝑢 ∈ ℝ (∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} ¬ 𝑢 < 𝑣 ∧ ∀𝑣 ∈ ℝ (𝑣 < 𝑢 → ∃𝑡 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣 < 𝑡)))
5856, 57mp3an1 1403 . . . 4 (({𝑤 ∈ ℝ ∣ -𝑤𝐴} ≠ ∅ ∧ ∃𝑢 ∈ ℝ ∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣𝑢) → ∃𝑢 ∈ ℝ (∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} ¬ 𝑢 < 𝑣 ∧ ∀𝑣 ∈ ℝ (𝑣 < 𝑢 → ∃𝑡 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣 < 𝑡)))
5955, 58syl6bi 242 . . 3 (𝐴 ⊆ ℝ → ((𝐴 ≠ ∅ ∧ ∃𝑥 ∈ ℝ ∀𝑦𝐴 𝑥𝑦) → ∃𝑢 ∈ ℝ (∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} ¬ 𝑢 < 𝑣 ∧ ∀𝑣 ∈ ℝ (𝑣 < 𝑢 → ∃𝑡 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣 < 𝑡))))
6015imbi1d 330 . . . . . . . . 9 (𝐴 ⊆ ℝ → ((𝑦𝐴 → ¬ 𝑦 < 𝑥) ↔ ((𝑦 ∈ ℝ ∧ 𝑦𝐴) → ¬ 𝑦 < 𝑥)))
61 impexp 461 . . . . . . . . 9 (((𝑦 ∈ ℝ ∧ 𝑦𝐴) → ¬ 𝑦 < 𝑥) ↔ (𝑦 ∈ ℝ → (𝑦𝐴 → ¬ 𝑦 < 𝑥)))
6260, 61syl6bb 275 . . . . . . . 8 (𝐴 ⊆ ℝ → ((𝑦𝐴 → ¬ 𝑦 < 𝑥) ↔ (𝑦 ∈ ℝ → (𝑦𝐴 → ¬ 𝑦 < 𝑥))))
6362albidv 1836 . . . . . . 7 (𝐴 ⊆ ℝ → (∀𝑦(𝑦𝐴 → ¬ 𝑦 < 𝑥) ↔ ∀𝑦(𝑦 ∈ ℝ → (𝑦𝐴 → ¬ 𝑦 < 𝑥))))
64 df-ral 2901 . . . . . . 7 (∀𝑦𝐴 ¬ 𝑦 < 𝑥 ↔ ∀𝑦(𝑦𝐴 → ¬ 𝑦 < 𝑥))
65 breq1 4586 . . . . . . . . . . 11 (𝑦 = -𝑣 → (𝑦 < 𝑥 ↔ -𝑣 < 𝑥))
6665notbid 307 . . . . . . . . . 10 (𝑦 = -𝑣 → (¬ 𝑦 < 𝑥 ↔ ¬ -𝑣 < 𝑥))
6723, 66imbi12d 333 . . . . . . . . 9 (𝑦 = -𝑣 → ((𝑦𝐴 → ¬ 𝑦 < 𝑥) ↔ (-𝑣𝐴 → ¬ -𝑣 < 𝑥)))
6821, 22, 67ralxfr 4812 . . . . . . . 8 (∀𝑦 ∈ ℝ (𝑦𝐴 → ¬ 𝑦 < 𝑥) ↔ ∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ -𝑣 < 𝑥))
69 df-ral 2901 . . . . . . . 8 (∀𝑦 ∈ ℝ (𝑦𝐴 → ¬ 𝑦 < 𝑥) ↔ ∀𝑦(𝑦 ∈ ℝ → (𝑦𝐴 → ¬ 𝑦 < 𝑥)))
7068, 69bitr3i 265 . . . . . . 7 (∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ -𝑣 < 𝑥) ↔ ∀𝑦(𝑦 ∈ ℝ → (𝑦𝐴 → ¬ 𝑦 < 𝑥)))
7163, 64, 703bitr4g 302 . . . . . 6 (𝐴 ⊆ ℝ → (∀𝑦𝐴 ¬ 𝑦 < 𝑥 ↔ ∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ -𝑣 < 𝑥)))
72 breq2 4587 . . . . . . . . 9 (𝑦 = -𝑣 → (𝑥 < 𝑦𝑥 < -𝑣))
73 breq2 4587 . . . . . . . . . 10 (𝑦 = -𝑣 → (𝑧 < 𝑦𝑧 < -𝑣))
7473rexbidv 3034 . . . . . . . . 9 (𝑦 = -𝑣 → (∃𝑧𝐴 𝑧 < 𝑦 ↔ ∃𝑧𝐴 𝑧 < -𝑣))
7572, 74imbi12d 333 . . . . . . . 8 (𝑦 = -𝑣 → ((𝑥 < 𝑦 → ∃𝑧𝐴 𝑧 < 𝑦) ↔ (𝑥 < -𝑣 → ∃𝑧𝐴 𝑧 < -𝑣)))
7621, 22, 75ralxfr 4812 . . . . . . 7 (∀𝑦 ∈ ℝ (𝑥 < 𝑦 → ∃𝑧𝐴 𝑧 < 𝑦) ↔ ∀𝑣 ∈ ℝ (𝑥 < -𝑣 → ∃𝑧𝐴 𝑧 < -𝑣))
77 ssel 3562 . . . . . . . . . . . . 13 (𝐴 ⊆ ℝ → (𝑧𝐴𝑧 ∈ ℝ))
7877adantrd 483 . . . . . . . . . . . 12 (𝐴 ⊆ ℝ → ((𝑧𝐴𝑧 < -𝑣) → 𝑧 ∈ ℝ))
7978pm4.71rd 665 . . . . . . . . . . 11 (𝐴 ⊆ ℝ → ((𝑧𝐴𝑧 < -𝑣) ↔ (𝑧 ∈ ℝ ∧ (𝑧𝐴𝑧 < -𝑣))))
8079exbidv 1837 . . . . . . . . . 10 (𝐴 ⊆ ℝ → (∃𝑧(𝑧𝐴𝑧 < -𝑣) ↔ ∃𝑧(𝑧 ∈ ℝ ∧ (𝑧𝐴𝑧 < -𝑣))))
81 df-rex 2902 . . . . . . . . . 10 (∃𝑧𝐴 𝑧 < -𝑣 ↔ ∃𝑧(𝑧𝐴𝑧 < -𝑣))
82 renegcl 10223 . . . . . . . . . . . 12 (𝑡 ∈ ℝ → -𝑡 ∈ ℝ)
83 infm3lem 10860 . . . . . . . . . . . 12 (𝑧 ∈ ℝ → ∃𝑡 ∈ ℝ 𝑧 = -𝑡)
84 eleq1 2676 . . . . . . . . . . . . 13 (𝑧 = -𝑡 → (𝑧𝐴 ↔ -𝑡𝐴))
85 breq1 4586 . . . . . . . . . . . . 13 (𝑧 = -𝑡 → (𝑧 < -𝑣 ↔ -𝑡 < -𝑣))
8684, 85anbi12d 743 . . . . . . . . . . . 12 (𝑧 = -𝑡 → ((𝑧𝐴𝑧 < -𝑣) ↔ (-𝑡𝐴 ∧ -𝑡 < -𝑣)))
8782, 83, 86rexxfr 4814 . . . . . . . . . . 11 (∃𝑧 ∈ ℝ (𝑧𝐴𝑧 < -𝑣) ↔ ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣))
88 df-rex 2902 . . . . . . . . . . 11 (∃𝑧 ∈ ℝ (𝑧𝐴𝑧 < -𝑣) ↔ ∃𝑧(𝑧 ∈ ℝ ∧ (𝑧𝐴𝑧 < -𝑣)))
8987, 88bitr3i 265 . . . . . . . . . 10 (∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣) ↔ ∃𝑧(𝑧 ∈ ℝ ∧ (𝑧𝐴𝑧 < -𝑣)))
9080, 81, 893bitr4g 302 . . . . . . . . 9 (𝐴 ⊆ ℝ → (∃𝑧𝐴 𝑧 < -𝑣 ↔ ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣)))
9190imbi2d 329 . . . . . . . 8 (𝐴 ⊆ ℝ → ((𝑥 < -𝑣 → ∃𝑧𝐴 𝑧 < -𝑣) ↔ (𝑥 < -𝑣 → ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣))))
9291ralbidv 2969 . . . . . . 7 (𝐴 ⊆ ℝ → (∀𝑣 ∈ ℝ (𝑥 < -𝑣 → ∃𝑧𝐴 𝑧 < -𝑣) ↔ ∀𝑣 ∈ ℝ (𝑥 < -𝑣 → ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣))))
9376, 92syl5bb 271 . . . . . 6 (𝐴 ⊆ ℝ → (∀𝑦 ∈ ℝ (𝑥 < 𝑦 → ∃𝑧𝐴 𝑧 < 𝑦) ↔ ∀𝑣 ∈ ℝ (𝑥 < -𝑣 → ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣))))
9471, 93anbi12d 743 . . . . 5 (𝐴 ⊆ ℝ → ((∀𝑦𝐴 ¬ 𝑦 < 𝑥 ∧ ∀𝑦 ∈ ℝ (𝑥 < 𝑦 → ∃𝑧𝐴 𝑧 < 𝑦)) ↔ (∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ -𝑣 < 𝑥) ∧ ∀𝑣 ∈ ℝ (𝑥 < -𝑣 → ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣)))))
9594rexbidv 3034 . . . 4 (𝐴 ⊆ ℝ → (∃𝑥 ∈ ℝ (∀𝑦𝐴 ¬ 𝑦 < 𝑥 ∧ ∀𝑦 ∈ ℝ (𝑥 < 𝑦 → ∃𝑧𝐴 𝑧 < 𝑦)) ↔ ∃𝑥 ∈ ℝ (∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ -𝑣 < 𝑥) ∧ ∀𝑣 ∈ ℝ (𝑥 < -𝑣 → ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣)))))
96 breq2 4587 . . . . . . . . . 10 (𝑥 = -𝑢 → (-𝑣 < 𝑥 ↔ -𝑣 < -𝑢))
9796notbid 307 . . . . . . . . 9 (𝑥 = -𝑢 → (¬ -𝑣 < 𝑥 ↔ ¬ -𝑣 < -𝑢))
9897imbi2d 329 . . . . . . . 8 (𝑥 = -𝑢 → ((-𝑣𝐴 → ¬ -𝑣 < 𝑥) ↔ (-𝑣𝐴 → ¬ -𝑣 < -𝑢)))
9998ralbidv 2969 . . . . . . 7 (𝑥 = -𝑢 → (∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ -𝑣 < 𝑥) ↔ ∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ -𝑣 < -𝑢)))
100 breq1 4586 . . . . . . . . 9 (𝑥 = -𝑢 → (𝑥 < -𝑣 ↔ -𝑢 < -𝑣))
101100imbi1d 330 . . . . . . . 8 (𝑥 = -𝑢 → ((𝑥 < -𝑣 → ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣)) ↔ (-𝑢 < -𝑣 → ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣))))
102101ralbidv 2969 . . . . . . 7 (𝑥 = -𝑢 → (∀𝑣 ∈ ℝ (𝑥 < -𝑣 → ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣)) ↔ ∀𝑣 ∈ ℝ (-𝑢 < -𝑣 → ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣))))
10399, 102anbi12d 743 . . . . . 6 (𝑥 = -𝑢 → ((∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ -𝑣 < 𝑥) ∧ ∀𝑣 ∈ ℝ (𝑥 < -𝑣 → ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣))) ↔ (∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ -𝑣 < -𝑢) ∧ ∀𝑣 ∈ ℝ (-𝑢 < -𝑣 → ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣)))))
10431, 32, 103rexxfr 4814 . . . . 5 (∃𝑥 ∈ ℝ (∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ -𝑣 < 𝑥) ∧ ∀𝑣 ∈ ℝ (𝑥 < -𝑣 → ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣))) ↔ ∃𝑢 ∈ ℝ (∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ -𝑣 < -𝑢) ∧ ∀𝑣 ∈ ℝ (-𝑢 < -𝑣 → ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣))))
10539imbi1i 338 . . . . . . . . . . 11 ((𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} → ¬ 𝑢 < 𝑣) ↔ ((𝑣 ∈ ℝ ∧ -𝑣𝐴) → ¬ 𝑢 < 𝑣))
106 impexp 461 . . . . . . . . . . 11 (((𝑣 ∈ ℝ ∧ -𝑣𝐴) → ¬ 𝑢 < 𝑣) ↔ (𝑣 ∈ ℝ → (-𝑣𝐴 → ¬ 𝑢 < 𝑣)))
107105, 106bitri 263 . . . . . . . . . 10 ((𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} → ¬ 𝑢 < 𝑣) ↔ (𝑣 ∈ ℝ → (-𝑣𝐴 → ¬ 𝑢 < 𝑣)))
108107albii 1737 . . . . . . . . 9 (∀𝑣(𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} → ¬ 𝑢 < 𝑣) ↔ ∀𝑣(𝑣 ∈ ℝ → (-𝑣𝐴 → ¬ 𝑢 < 𝑣)))
109 df-ral 2901 . . . . . . . . 9 (∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} ¬ 𝑢 < 𝑣 ↔ ∀𝑣(𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} → ¬ 𝑢 < 𝑣))
110 df-ral 2901 . . . . . . . . 9 (∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ 𝑢 < 𝑣) ↔ ∀𝑣(𝑣 ∈ ℝ → (-𝑣𝐴 → ¬ 𝑢 < 𝑣)))
111108, 109, 1103bitr4ri 292 . . . . . . . 8 (∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ 𝑢 < 𝑣) ↔ ∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} ¬ 𝑢 < 𝑣)
112 ltneg 10407 . . . . . . . . . . 11 ((𝑢 ∈ ℝ ∧ 𝑣 ∈ ℝ) → (𝑢 < 𝑣 ↔ -𝑣 < -𝑢))
113112notbid 307 . . . . . . . . . 10 ((𝑢 ∈ ℝ ∧ 𝑣 ∈ ℝ) → (¬ 𝑢 < 𝑣 ↔ ¬ -𝑣 < -𝑢))
114113imbi2d 329 . . . . . . . . 9 ((𝑢 ∈ ℝ ∧ 𝑣 ∈ ℝ) → ((-𝑣𝐴 → ¬ 𝑢 < 𝑣) ↔ (-𝑣𝐴 → ¬ -𝑣 < -𝑢)))
115114ralbidva 2968 . . . . . . . 8 (𝑢 ∈ ℝ → (∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ 𝑢 < 𝑣) ↔ ∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ -𝑣 < -𝑢)))
116111, 115syl5bbr 273 . . . . . . 7 (𝑢 ∈ ℝ → (∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} ¬ 𝑢 < 𝑣 ↔ ∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ -𝑣 < -𝑢)))
117 ltneg 10407 . . . . . . . . . 10 ((𝑣 ∈ ℝ ∧ 𝑢 ∈ ℝ) → (𝑣 < 𝑢 ↔ -𝑢 < -𝑣))
118117ancoms 468 . . . . . . . . 9 ((𝑢 ∈ ℝ ∧ 𝑣 ∈ ℝ) → (𝑣 < 𝑢 ↔ -𝑢 < -𝑣))
119 negeq 10152 . . . . . . . . . . . . 13 (𝑤 = 𝑡 → -𝑤 = -𝑡)
120119eleq1d 2672 . . . . . . . . . . . 12 (𝑤 = 𝑡 → (-𝑤𝐴 ↔ -𝑡𝐴))
121120rexrab 3337 . . . . . . . . . . 11 (∃𝑡 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣 < 𝑡 ↔ ∃𝑡 ∈ ℝ (-𝑡𝐴𝑣 < 𝑡))
122 ltneg 10407 . . . . . . . . . . . . 13 ((𝑣 ∈ ℝ ∧ 𝑡 ∈ ℝ) → (𝑣 < 𝑡 ↔ -𝑡 < -𝑣))
123122anbi2d 736 . . . . . . . . . . . 12 ((𝑣 ∈ ℝ ∧ 𝑡 ∈ ℝ) → ((-𝑡𝐴𝑣 < 𝑡) ↔ (-𝑡𝐴 ∧ -𝑡 < -𝑣)))
124123rexbidva 3031 . . . . . . . . . . 11 (𝑣 ∈ ℝ → (∃𝑡 ∈ ℝ (-𝑡𝐴𝑣 < 𝑡) ↔ ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣)))
125121, 124syl5bb 271 . . . . . . . . . 10 (𝑣 ∈ ℝ → (∃𝑡 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣 < 𝑡 ↔ ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣)))
126125adantl 481 . . . . . . . . 9 ((𝑢 ∈ ℝ ∧ 𝑣 ∈ ℝ) → (∃𝑡 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣 < 𝑡 ↔ ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣)))
127118, 126imbi12d 333 . . . . . . . 8 ((𝑢 ∈ ℝ ∧ 𝑣 ∈ ℝ) → ((𝑣 < 𝑢 → ∃𝑡 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣 < 𝑡) ↔ (-𝑢 < -𝑣 → ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣))))
128127ralbidva 2968 . . . . . . 7 (𝑢 ∈ ℝ → (∀𝑣 ∈ ℝ (𝑣 < 𝑢 → ∃𝑡 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣 < 𝑡) ↔ ∀𝑣 ∈ ℝ (-𝑢 < -𝑣 → ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣))))
129116, 128anbi12d 743 . . . . . 6 (𝑢 ∈ ℝ → ((∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} ¬ 𝑢 < 𝑣 ∧ ∀𝑣 ∈ ℝ (𝑣 < 𝑢 → ∃𝑡 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣 < 𝑡)) ↔ (∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ -𝑣 < -𝑢) ∧ ∀𝑣 ∈ ℝ (-𝑢 < -𝑣 → ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣)))))
130129rexbiia 3022 . . . . 5 (∃𝑢 ∈ ℝ (∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} ¬ 𝑢 < 𝑣 ∧ ∀𝑣 ∈ ℝ (𝑣 < 𝑢 → ∃𝑡 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣 < 𝑡)) ↔ ∃𝑢 ∈ ℝ (∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ -𝑣 < -𝑢) ∧ ∀𝑣 ∈ ℝ (-𝑢 < -𝑣 → ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣))))
131104, 130bitr4i 266 . . . 4 (∃𝑥 ∈ ℝ (∀𝑣 ∈ ℝ (-𝑣𝐴 → ¬ -𝑣 < 𝑥) ∧ ∀𝑣 ∈ ℝ (𝑥 < -𝑣 → ∃𝑡 ∈ ℝ (-𝑡𝐴 ∧ -𝑡 < -𝑣))) ↔ ∃𝑢 ∈ ℝ (∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} ¬ 𝑢 < 𝑣 ∧ ∀𝑣 ∈ ℝ (𝑣 < 𝑢 → ∃𝑡 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣 < 𝑡)))
13295, 131syl6bb 275 . . 3 (𝐴 ⊆ ℝ → (∃𝑥 ∈ ℝ (∀𝑦𝐴 ¬ 𝑦 < 𝑥 ∧ ∀𝑦 ∈ ℝ (𝑥 < 𝑦 → ∃𝑧𝐴 𝑧 < 𝑦)) ↔ ∃𝑢 ∈ ℝ (∀𝑣 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴} ¬ 𝑢 < 𝑣 ∧ ∀𝑣 ∈ ℝ (𝑣 < 𝑢 → ∃𝑡 ∈ {𝑤 ∈ ℝ ∣ -𝑤𝐴}𝑣 < 𝑡))))
13359, 132sylibrd 248 . 2 (𝐴 ⊆ ℝ → ((𝐴 ≠ ∅ ∧ ∃𝑥 ∈ ℝ ∀𝑦𝐴 𝑥𝑦) → ∃𝑥 ∈ ℝ (∀𝑦𝐴 ¬ 𝑦 < 𝑥 ∧ ∀𝑦 ∈ ℝ (𝑥 < 𝑦 → ∃𝑧𝐴 𝑧 < 𝑦))))
1341333impib 1254 1 ((𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ∧ ∃𝑥 ∈ ℝ ∀𝑦𝐴 𝑥𝑦) → ∃𝑥 ∈ ℝ (∀𝑦𝐴 ¬ 𝑦 < 𝑥 ∧ ∀𝑦 ∈ ℝ (𝑥 < 𝑦 → ∃𝑧𝐴 𝑧 < 𝑦)))
 Colors of variables: wff setvar class Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 195   ∧ wa 383   ∧ w3a 1031  ∀wal 1473   = wceq 1475  ∃wex 1695   ∈ wcel 1977   ≠ wne 2780  ∀wral 2896  ∃wrex 2897  {crab 2900   ⊆ wss 3540  ∅c0 3874   class class class wbr 4583  ℝcr 9814   < clt 9953   ≤ cle 9954  -cneg 10146 This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1713  ax-4 1728  ax-5 1827  ax-6 1875  ax-7 1922  ax-8 1979  ax-9 1986  ax-10 2006  ax-11 2021  ax-12 2034  ax-13 2234  ax-ext 2590  ax-sep 4709  ax-nul 4717  ax-pow 4769  ax-pr 4833  ax-un 6847  ax-resscn 9872  ax-1cn 9873  ax-icn 9874  ax-addcl 9875  ax-addrcl 9876  ax-mulcl 9877  ax-mulrcl 9878  ax-mulcom 9879  ax-addass 9880  ax-mulass 9881  ax-distr 9882  ax-i2m1 9883  ax-1ne0 9884  ax-1rid 9885  ax-rnegex 9886  ax-rrecex 9887  ax-cnre 9888  ax-pre-lttri 9889  ax-pre-lttrn 9890  ax-pre-ltadd 9891  ax-pre-mulgt0 9892  ax-pre-sup 9893 This theorem depends on definitions:  df-bi 196  df-or 384  df-an 385  df-3or 1032  df-3an 1033  df-tru 1478  df-ex 1696  df-nf 1701  df-sb 1868  df-eu 2462  df-mo 2463  df-clab 2597  df-cleq 2603  df-clel 2606  df-nfc 2740  df-ne 2782  df-nel 2783  df-ral 2901  df-rex 2902  df-reu 2903  df-rab 2905  df-v 3175  df-sbc 3403  df-csb 3500  df-dif 3543  df-un 3545  df-in 3547  df-ss 3554  df-nul 3875  df-if 4037  df-pw 4110  df-sn 4126  df-pr 4128  df-op 4132  df-uni 4373  df-br 4584  df-opab 4644  df-mpt 4645  df-id 4953  df-po 4959  df-so 4960  df-xp 5044  df-rel 5045  df-cnv 5046  df-co 5047  df-dm 5048  df-rn 5049  df-res 5050  df-ima 5051  df-iota 5768  df-fun 5806  df-fn 5807  df-f 5808  df-f1 5809  df-fo 5810  df-f1o 5811  df-fv 5812  df-riota 6511  df-ov 6552  df-oprab 6553  df-mpt2 6554  df-er 7629  df-en 7842  df-dom 7843  df-sdom 7844  df-pnf 9955  df-mnf 9956  df-xr 9957  df-ltxr 9958  df-le 9959  df-sub 10147  df-neg 10148 This theorem is referenced by:  infrecl  10882  infrenegsup  10883  infregelb  10884  infrelb  10885  xrinfmsslem  12010  gtinf  31483  gtinfOLD  31484  infrglb  38657
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