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Mirrors > Home > MPE Home > Th. List > btwnz | Structured version Visualization version GIF version |
Description: Any real number can be sandwiched between two integers. Exercise 2 of [Apostol] p. 28. (Contributed by NM, 10-Nov-2004.) |
Ref | Expression |
---|---|
btwnz | ⊢ (𝐴 ∈ ℝ → (∃𝑥 ∈ ℤ 𝑥 < 𝐴 ∧ ∃𝑦 ∈ ℤ 𝐴 < 𝑦)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | renegcl 11520 | . . . 4 ⊢ (𝐴 ∈ ℝ → -𝐴 ∈ ℝ) | |
2 | arch 12466 | . . . 4 ⊢ (-𝐴 ∈ ℝ → ∃𝑧 ∈ ℕ -𝐴 < 𝑧) | |
3 | 1, 2 | syl 17 | . . 3 ⊢ (𝐴 ∈ ℝ → ∃𝑧 ∈ ℕ -𝐴 < 𝑧) |
4 | nnre 12216 | . . . . . . . 8 ⊢ (𝑧 ∈ ℕ → 𝑧 ∈ ℝ) | |
5 | ltnegcon1 11712 | . . . . . . . . 9 ⊢ ((𝐴 ∈ ℝ ∧ 𝑧 ∈ ℝ) → (-𝐴 < 𝑧 ↔ -𝑧 < 𝐴)) | |
6 | 5 | ex 412 | . . . . . . . 8 ⊢ (𝐴 ∈ ℝ → (𝑧 ∈ ℝ → (-𝐴 < 𝑧 ↔ -𝑧 < 𝐴))) |
7 | 4, 6 | syl5 34 | . . . . . . 7 ⊢ (𝐴 ∈ ℝ → (𝑧 ∈ ℕ → (-𝐴 < 𝑧 ↔ -𝑧 < 𝐴))) |
8 | 7 | pm5.32d 576 | . . . . . 6 ⊢ (𝐴 ∈ ℝ → ((𝑧 ∈ ℕ ∧ -𝐴 < 𝑧) ↔ (𝑧 ∈ ℕ ∧ -𝑧 < 𝐴))) |
9 | nnnegz 12558 | . . . . . . 7 ⊢ (𝑧 ∈ ℕ → -𝑧 ∈ ℤ) | |
10 | breq1 5141 | . . . . . . . 8 ⊢ (𝑥 = -𝑧 → (𝑥 < 𝐴 ↔ -𝑧 < 𝐴)) | |
11 | 10 | rspcev 3604 | . . . . . . 7 ⊢ ((-𝑧 ∈ ℤ ∧ -𝑧 < 𝐴) → ∃𝑥 ∈ ℤ 𝑥 < 𝐴) |
12 | 9, 11 | sylan 579 | . . . . . 6 ⊢ ((𝑧 ∈ ℕ ∧ -𝑧 < 𝐴) → ∃𝑥 ∈ ℤ 𝑥 < 𝐴) |
13 | 8, 12 | biimtrdi 252 | . . . . 5 ⊢ (𝐴 ∈ ℝ → ((𝑧 ∈ ℕ ∧ -𝐴 < 𝑧) → ∃𝑥 ∈ ℤ 𝑥 < 𝐴)) |
14 | 13 | expd 415 | . . . 4 ⊢ (𝐴 ∈ ℝ → (𝑧 ∈ ℕ → (-𝐴 < 𝑧 → ∃𝑥 ∈ ℤ 𝑥 < 𝐴))) |
15 | 14 | rexlimdv 3145 | . . 3 ⊢ (𝐴 ∈ ℝ → (∃𝑧 ∈ ℕ -𝐴 < 𝑧 → ∃𝑥 ∈ ℤ 𝑥 < 𝐴)) |
16 | 3, 15 | mpd 15 | . 2 ⊢ (𝐴 ∈ ℝ → ∃𝑥 ∈ ℤ 𝑥 < 𝐴) |
17 | arch 12466 | . . 3 ⊢ (𝐴 ∈ ℝ → ∃𝑦 ∈ ℕ 𝐴 < 𝑦) | |
18 | nnz 12576 | . . . . 5 ⊢ (𝑦 ∈ ℕ → 𝑦 ∈ ℤ) | |
19 | 18 | anim1i 614 | . . . 4 ⊢ ((𝑦 ∈ ℕ ∧ 𝐴 < 𝑦) → (𝑦 ∈ ℤ ∧ 𝐴 < 𝑦)) |
20 | 19 | reximi2 3071 | . . 3 ⊢ (∃𝑦 ∈ ℕ 𝐴 < 𝑦 → ∃𝑦 ∈ ℤ 𝐴 < 𝑦) |
21 | 17, 20 | syl 17 | . 2 ⊢ (𝐴 ∈ ℝ → ∃𝑦 ∈ ℤ 𝐴 < 𝑦) |
22 | 16, 21 | jca 511 | 1 ⊢ (𝐴 ∈ ℝ → (∃𝑥 ∈ ℤ 𝑥 < 𝐴 ∧ ∃𝑦 ∈ ℤ 𝐴 < 𝑦)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 205 ∧ wa 395 ∈ wcel 2098 ∃wrex 3062 class class class wbr 5138 ℝcr 11105 < clt 11245 -cneg 11442 ℕcn 12209 ℤcz 12555 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1789 ax-4 1803 ax-5 1905 ax-6 1963 ax-7 2003 ax-8 2100 ax-9 2108 ax-10 2129 ax-11 2146 ax-12 2163 ax-ext 2695 ax-sep 5289 ax-nul 5296 ax-pow 5353 ax-pr 5417 ax-un 7718 ax-resscn 11163 ax-1cn 11164 ax-icn 11165 ax-addcl 11166 ax-addrcl 11167 ax-mulcl 11168 ax-mulrcl 11169 ax-mulcom 11170 ax-addass 11171 ax-mulass 11172 ax-distr 11173 ax-i2m1 11174 ax-1ne0 11175 ax-1rid 11176 ax-rnegex 11177 ax-rrecex 11178 ax-cnre 11179 ax-pre-lttri 11180 ax-pre-lttrn 11181 ax-pre-ltadd 11182 ax-pre-mulgt0 11183 ax-pre-sup 11184 |
This theorem depends on definitions: df-bi 206 df-an 396 df-or 845 df-3or 1085 df-3an 1086 df-tru 1536 df-fal 1546 df-ex 1774 df-nf 1778 df-sb 2060 df-mo 2526 df-eu 2555 df-clab 2702 df-cleq 2716 df-clel 2802 df-nfc 2877 df-ne 2933 df-nel 3039 df-ral 3054 df-rex 3063 df-reu 3369 df-rab 3425 df-v 3468 df-sbc 3770 df-csb 3886 df-dif 3943 df-un 3945 df-in 3947 df-ss 3957 df-pss 3959 df-nul 4315 df-if 4521 df-pw 4596 df-sn 4621 df-pr 4623 df-op 4627 df-uni 4900 df-iun 4989 df-br 5139 df-opab 5201 df-mpt 5222 df-tr 5256 df-id 5564 df-eprel 5570 df-po 5578 df-so 5579 df-fr 5621 df-we 5623 df-xp 5672 df-rel 5673 df-cnv 5674 df-co 5675 df-dm 5676 df-rn 5677 df-res 5678 df-ima 5679 df-pred 6290 df-ord 6357 df-on 6358 df-lim 6359 df-suc 6360 df-iota 6485 df-fun 6535 df-fn 6536 df-f 6537 df-f1 6538 df-fo 6539 df-f1o 6540 df-fv 6541 df-riota 7357 df-ov 7404 df-oprab 7405 df-mpo 7406 df-om 7849 df-2nd 7969 df-frecs 8261 df-wrecs 8292 df-recs 8366 df-rdg 8405 df-er 8699 df-en 8936 df-dom 8937 df-sdom 8938 df-pnf 11247 df-mnf 11248 df-xr 11249 df-ltxr 11250 df-le 11251 df-sub 11443 df-neg 11444 df-nn 12210 df-z 12556 |
This theorem is referenced by: lbzbi 12917 rpnnen1lem2 12958 rpnnen1lem1 12959 rpnnen1lem3 12960 rpnnen1lem5 12962 fourierdlem64 45371 |
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