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Mirrors > Home > ILE Home > Th. List > ioo0 | GIF version |
Description: An empty open interval of extended reals. (Contributed by NM, 6-Feb-2007.) |
Ref | Expression |
---|---|
ioo0 | ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ*) → ((𝐴(,)𝐵) = ∅ ↔ 𝐵 ≤ 𝐴)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | iooval 9532 | . . 3 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ*) → (𝐴(,)𝐵) = {𝑥 ∈ ℝ* ∣ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵)}) | |
2 | 1 | eqeq1d 2108 | . 2 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ*) → ((𝐴(,)𝐵) = ∅ ↔ {𝑥 ∈ ℝ* ∣ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵)} = ∅)) |
3 | xrlttr 9422 | . . . . . . . 8 ⊢ ((𝐴 ∈ ℝ* ∧ 𝑥 ∈ ℝ* ∧ 𝐵 ∈ ℝ*) → ((𝐴 < 𝑥 ∧ 𝑥 < 𝐵) → 𝐴 < 𝐵)) | |
4 | 3 | 3com23 1155 | . . . . . . 7 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝑥 ∈ ℝ*) → ((𝐴 < 𝑥 ∧ 𝑥 < 𝐵) → 𝐴 < 𝐵)) |
5 | 4 | 3expa 1149 | . . . . . 6 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ*) ∧ 𝑥 ∈ ℝ*) → ((𝐴 < 𝑥 ∧ 𝑥 < 𝐵) → 𝐴 < 𝐵)) |
6 | 5 | rexlimdva 2508 | . . . . 5 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ*) → (∃𝑥 ∈ ℝ* (𝐴 < 𝑥 ∧ 𝑥 < 𝐵) → 𝐴 < 𝐵)) |
7 | qbtwnxr 9876 | . . . . . . 7 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐴 < 𝐵) → ∃𝑥 ∈ ℚ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵)) | |
8 | qre 9267 | . . . . . . . . . 10 ⊢ (𝑥 ∈ ℚ → 𝑥 ∈ ℝ) | |
9 | 8 | rexrd 7687 | . . . . . . . . 9 ⊢ (𝑥 ∈ ℚ → 𝑥 ∈ ℝ*) |
10 | 9 | anim1i 336 | . . . . . . . 8 ⊢ ((𝑥 ∈ ℚ ∧ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵)) → (𝑥 ∈ ℝ* ∧ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵))) |
11 | 10 | reximi2 2487 | . . . . . . 7 ⊢ (∃𝑥 ∈ ℚ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵) → ∃𝑥 ∈ ℝ* (𝐴 < 𝑥 ∧ 𝑥 < 𝐵)) |
12 | 7, 11 | syl 14 | . . . . . 6 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ∧ 𝐴 < 𝐵) → ∃𝑥 ∈ ℝ* (𝐴 < 𝑥 ∧ 𝑥 < 𝐵)) |
13 | 12 | 3expia 1151 | . . . . 5 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ*) → (𝐴 < 𝐵 → ∃𝑥 ∈ ℝ* (𝐴 < 𝑥 ∧ 𝑥 < 𝐵))) |
14 | 6, 13 | impbid 128 | . . . 4 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ*) → (∃𝑥 ∈ ℝ* (𝐴 < 𝑥 ∧ 𝑥 < 𝐵) ↔ 𝐴 < 𝐵)) |
15 | 14 | notbid 633 | . . 3 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ*) → (¬ ∃𝑥 ∈ ℝ* (𝐴 < 𝑥 ∧ 𝑥 < 𝐵) ↔ ¬ 𝐴 < 𝐵)) |
16 | rabeq0 3339 | . . . . 5 ⊢ ({𝑥 ∈ ℝ* ∣ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵)} = ∅ ↔ ∀𝑥 ∈ ℝ* ¬ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵)) | |
17 | ralnex 2385 | . . . . 5 ⊢ (∀𝑥 ∈ ℝ* ¬ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵) ↔ ¬ ∃𝑥 ∈ ℝ* (𝐴 < 𝑥 ∧ 𝑥 < 𝐵)) | |
18 | 16, 17 | bitri 183 | . . . 4 ⊢ ({𝑥 ∈ ℝ* ∣ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵)} = ∅ ↔ ¬ ∃𝑥 ∈ ℝ* (𝐴 < 𝑥 ∧ 𝑥 < 𝐵)) |
19 | 18 | a1i 9 | . . 3 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ*) → ({𝑥 ∈ ℝ* ∣ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵)} = ∅ ↔ ¬ ∃𝑥 ∈ ℝ* (𝐴 < 𝑥 ∧ 𝑥 < 𝐵))) |
20 | xrlenlt 7701 | . . . 4 ⊢ ((𝐵 ∈ ℝ* ∧ 𝐴 ∈ ℝ*) → (𝐵 ≤ 𝐴 ↔ ¬ 𝐴 < 𝐵)) | |
21 | 20 | ancoms 266 | . . 3 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ*) → (𝐵 ≤ 𝐴 ↔ ¬ 𝐴 < 𝐵)) |
22 | 15, 19, 21 | 3bitr4d 219 | . 2 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ*) → ({𝑥 ∈ ℝ* ∣ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵)} = ∅ ↔ 𝐵 ≤ 𝐴)) |
23 | 2, 22 | bitrd 187 | 1 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ*) → ((𝐴(,)𝐵) = ∅ ↔ 𝐵 ≤ 𝐴)) |
Colors of variables: wff set class |
Syntax hints: ¬ wn 3 → wi 4 ∧ wa 103 ↔ wb 104 ∧ w3a 930 = wceq 1299 ∈ wcel 1448 ∀wral 2375 ∃wrex 2376 {crab 2379 ∅c0 3310 class class class wbr 3875 (class class class)co 5706 ℝ*cxr 7671 < clt 7672 ≤ cle 7673 ℚcq 9261 (,)cioo 9512 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 105 ax-ia2 106 ax-ia3 107 ax-in1 584 ax-in2 585 ax-io 671 ax-5 1391 ax-7 1392 ax-gen 1393 ax-ie1 1437 ax-ie2 1438 ax-8 1450 ax-10 1451 ax-11 1452 ax-i12 1453 ax-bndl 1454 ax-4 1455 ax-13 1459 ax-14 1460 ax-17 1474 ax-i9 1478 ax-ial 1482 ax-i5r 1483 ax-ext 2082 ax-sep 3986 ax-pow 4038 ax-pr 4069 ax-un 4293 ax-setind 4390 ax-cnex 7586 ax-resscn 7587 ax-1cn 7588 ax-1re 7589 ax-icn 7590 ax-addcl 7591 ax-addrcl 7592 ax-mulcl 7593 ax-mulrcl 7594 ax-addcom 7595 ax-mulcom 7596 ax-addass 7597 ax-mulass 7598 ax-distr 7599 ax-i2m1 7600 ax-0lt1 7601 ax-1rid 7602 ax-0id 7603 ax-rnegex 7604 ax-precex 7605 ax-cnre 7606 ax-pre-ltirr 7607 ax-pre-ltwlin 7608 ax-pre-lttrn 7609 ax-pre-apti 7610 ax-pre-ltadd 7611 ax-pre-mulgt0 7612 ax-pre-mulext 7613 ax-arch 7614 |
This theorem depends on definitions: df-bi 116 df-3or 931 df-3an 932 df-tru 1302 df-fal 1305 df-nf 1405 df-sb 1704 df-eu 1963 df-mo 1964 df-clab 2087 df-cleq 2093 df-clel 2096 df-nfc 2229 df-ne 2268 df-nel 2363 df-ral 2380 df-rex 2381 df-reu 2382 df-rmo 2383 df-rab 2384 df-v 2643 df-sbc 2863 df-csb 2956 df-dif 3023 df-un 3025 df-in 3027 df-ss 3034 df-nul 3311 df-pw 3459 df-sn 3480 df-pr 3481 df-op 3483 df-uni 3684 df-int 3719 df-iun 3762 df-br 3876 df-opab 3930 df-mpt 3931 df-id 4153 df-po 4156 df-iso 4157 df-xp 4483 df-rel 4484 df-cnv 4485 df-co 4486 df-dm 4487 df-rn 4488 df-res 4489 df-ima 4490 df-iota 5024 df-fun 5061 df-fn 5062 df-f 5063 df-fv 5067 df-riota 5662 df-ov 5709 df-oprab 5710 df-mpo 5711 df-1st 5969 df-2nd 5970 df-pnf 7674 df-mnf 7675 df-xr 7676 df-ltxr 7677 df-le 7678 df-sub 7806 df-neg 7807 df-reap 8203 df-ap 8210 df-div 8294 df-inn 8579 df-2 8637 df-n0 8830 df-z 8907 df-uz 9177 df-q 9262 df-rp 9292 df-ioo 9516 |
This theorem is referenced by: (None) |
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