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Mirrors > Home > ILE Home > Th. List > arch | GIF version |
Description: Archimedean property of real numbers. For any real number, there is an integer greater than it. Theorem I.29 of [Apostol] p. 26. (Contributed by NM, 21-Jan-1997.) |
Ref | Expression |
---|---|
arch | ⊢ (𝐴 ∈ ℝ → ∃𝑛 ∈ ℕ 𝐴 < 𝑛) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ax-arch 7366 | . . 3 ⊢ (𝐴 ∈ ℝ → ∃𝑛 ∈ ∩ {𝑥 ∣ (1 ∈ 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑦 + 1) ∈ 𝑥)}𝐴 <ℝ 𝑛) | |
2 | dfnn2 8317 | . . . 4 ⊢ ℕ = ∩ {𝑥 ∣ (1 ∈ 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑦 + 1) ∈ 𝑥)} | |
3 | 2 | rexeqi 2560 | . . 3 ⊢ (∃𝑛 ∈ ℕ 𝐴 <ℝ 𝑛 ↔ ∃𝑛 ∈ ∩ {𝑥 ∣ (1 ∈ 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑦 + 1) ∈ 𝑥)}𝐴 <ℝ 𝑛) |
4 | 1, 3 | sylibr 132 | . 2 ⊢ (𝐴 ∈ ℝ → ∃𝑛 ∈ ℕ 𝐴 <ℝ 𝑛) |
5 | nnre 8322 | . . . 4 ⊢ (𝑛 ∈ ℕ → 𝑛 ∈ ℝ) | |
6 | ltxrlt 7454 | . . . 4 ⊢ ((𝐴 ∈ ℝ ∧ 𝑛 ∈ ℝ) → (𝐴 < 𝑛 ↔ 𝐴 <ℝ 𝑛)) | |
7 | 5, 6 | sylan2 280 | . . 3 ⊢ ((𝐴 ∈ ℝ ∧ 𝑛 ∈ ℕ) → (𝐴 < 𝑛 ↔ 𝐴 <ℝ 𝑛)) |
8 | 7 | rexbidva 2371 | . 2 ⊢ (𝐴 ∈ ℝ → (∃𝑛 ∈ ℕ 𝐴 < 𝑛 ↔ ∃𝑛 ∈ ℕ 𝐴 <ℝ 𝑛)) |
9 | 4, 8 | mpbird 165 | 1 ⊢ (𝐴 ∈ ℝ → ∃𝑛 ∈ ℕ 𝐴 < 𝑛) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 102 ↔ wb 103 ∈ wcel 1434 {cab 2069 ∀wral 2353 ∃wrex 2354 ∩ cint 3662 class class class wbr 3811 (class class class)co 5590 ℝcr 7251 1c1 7253 + caddc 7255 <ℝ cltrr 7256 < clt 7424 ℕcn 8315 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 104 ax-ia2 105 ax-ia3 106 ax-in1 577 ax-in2 578 ax-io 663 ax-5 1377 ax-7 1378 ax-gen 1379 ax-ie1 1423 ax-ie2 1424 ax-8 1436 ax-10 1437 ax-11 1438 ax-i12 1439 ax-bndl 1440 ax-4 1441 ax-13 1445 ax-14 1446 ax-17 1460 ax-i9 1464 ax-ial 1468 ax-i5r 1469 ax-ext 2065 ax-sep 3922 ax-pow 3974 ax-pr 3999 ax-un 4223 ax-setind 4315 ax-cnex 7338 ax-resscn 7339 ax-1re 7341 ax-addrcl 7344 ax-arch 7366 |
This theorem depends on definitions: df-bi 115 df-3an 922 df-tru 1288 df-fal 1291 df-nf 1391 df-sb 1688 df-eu 1946 df-mo 1947 df-clab 2070 df-cleq 2076 df-clel 2079 df-nfc 2212 df-ne 2250 df-nel 2345 df-ral 2358 df-rex 2359 df-rab 2362 df-v 2614 df-dif 2986 df-un 2988 df-in 2990 df-ss 2997 df-pw 3408 df-sn 3428 df-pr 3429 df-op 3431 df-uni 3628 df-int 3663 df-br 3812 df-opab 3866 df-xp 4406 df-pnf 7426 df-mnf 7427 df-ltxr 7429 df-inn 8316 |
This theorem is referenced by: nnrecl 8562 bndndx 8563 btwnz 8760 expnbnd 9911 cvg1nlemres 10244 cvg1n 10245 resqrexlemga 10282 alzdvds 10634 dvdsbnd 10727 |
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