![]() |
Mathbox for Alexander van der Vekens |
< Previous
Next >
Nearby theorems |
|
Mirrors > Home > MPE Home > Th. List > Mathboxes > nnoALTV | Structured version Visualization version GIF version |
Description: An alternate characterization of an odd number greater than 1. (Contributed by AV, 2-Jun-2020.) (Revised by AV, 21-Jun-2020.) |
Ref | Expression |
---|---|
nnoALTV | ⊢ ((𝑁 ∈ (ℤ≥‘2) ∧ 𝑁 ∈ Odd ) → ((𝑁 − 1) / 2) ∈ ℕ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | oddm1div2z 43107 | . . 3 ⊢ (𝑁 ∈ Odd → ((𝑁 − 1) / 2) ∈ ℤ) | |
2 | 1 | adantl 474 | . 2 ⊢ ((𝑁 ∈ (ℤ≥‘2) ∧ 𝑁 ∈ Odd ) → ((𝑁 − 1) / 2) ∈ ℤ) |
3 | eluz2b1 12126 | . . . 4 ⊢ (𝑁 ∈ (ℤ≥‘2) ↔ (𝑁 ∈ ℤ ∧ 1 < 𝑁)) | |
4 | 1red 10432 | . . . . . . 7 ⊢ (𝑁 ∈ ℤ → 1 ∈ ℝ) | |
5 | zre 11790 | . . . . . . 7 ⊢ (𝑁 ∈ ℤ → 𝑁 ∈ ℝ) | |
6 | 4, 5 | posdifd 11020 | . . . . . 6 ⊢ (𝑁 ∈ ℤ → (1 < 𝑁 ↔ 0 < (𝑁 − 1))) |
7 | 6 | biimpa 469 | . . . . 5 ⊢ ((𝑁 ∈ ℤ ∧ 1 < 𝑁) → 0 < (𝑁 − 1)) |
8 | peano2zm 11831 | . . . . . . . . 9 ⊢ (𝑁 ∈ ℤ → (𝑁 − 1) ∈ ℤ) | |
9 | 8 | zred 11893 | . . . . . . . 8 ⊢ (𝑁 ∈ ℤ → (𝑁 − 1) ∈ ℝ) |
10 | 2re 11507 | . . . . . . . . 9 ⊢ 2 ∈ ℝ | |
11 | 10 | a1i 11 | . . . . . . . 8 ⊢ (𝑁 ∈ ℤ → 2 ∈ ℝ) |
12 | 2pos 11543 | . . . . . . . . 9 ⊢ 0 < 2 | |
13 | 12 | a1i 11 | . . . . . . . 8 ⊢ (𝑁 ∈ ℤ → 0 < 2) |
14 | 9, 11, 13 | 3jca 1108 | . . . . . . 7 ⊢ (𝑁 ∈ ℤ → ((𝑁 − 1) ∈ ℝ ∧ 2 ∈ ℝ ∧ 0 < 2)) |
15 | 14 | adantr 473 | . . . . . 6 ⊢ ((𝑁 ∈ ℤ ∧ 1 < 𝑁) → ((𝑁 − 1) ∈ ℝ ∧ 2 ∈ ℝ ∧ 0 < 2)) |
16 | gt0div 11299 | . . . . . 6 ⊢ (((𝑁 − 1) ∈ ℝ ∧ 2 ∈ ℝ ∧ 0 < 2) → (0 < (𝑁 − 1) ↔ 0 < ((𝑁 − 1) / 2))) | |
17 | 15, 16 | syl 17 | . . . . 5 ⊢ ((𝑁 ∈ ℤ ∧ 1 < 𝑁) → (0 < (𝑁 − 1) ↔ 0 < ((𝑁 − 1) / 2))) |
18 | 7, 17 | mpbid 224 | . . . 4 ⊢ ((𝑁 ∈ ℤ ∧ 1 < 𝑁) → 0 < ((𝑁 − 1) / 2)) |
19 | 3, 18 | sylbi 209 | . . 3 ⊢ (𝑁 ∈ (ℤ≥‘2) → 0 < ((𝑁 − 1) / 2)) |
20 | 19 | adantr 473 | . 2 ⊢ ((𝑁 ∈ (ℤ≥‘2) ∧ 𝑁 ∈ Odd ) → 0 < ((𝑁 − 1) / 2)) |
21 | elnnz 11796 | . 2 ⊢ (((𝑁 − 1) / 2) ∈ ℕ ↔ (((𝑁 − 1) / 2) ∈ ℤ ∧ 0 < ((𝑁 − 1) / 2))) | |
22 | 2, 20, 21 | sylanbrc 575 | 1 ⊢ ((𝑁 ∈ (ℤ≥‘2) ∧ 𝑁 ∈ Odd ) → ((𝑁 − 1) / 2) ∈ ℕ) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 198 ∧ wa 387 ∧ w3a 1068 ∈ wcel 2048 class class class wbr 4923 ‘cfv 6182 (class class class)co 6970 ℝcr 10326 0cc0 10327 1c1 10328 < clt 10466 − cmin 10662 / cdiv 11090 ℕcn 11431 2c2 11488 ℤcz 11786 ℤ≥cuz 12051 Odd codd 43098 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1758 ax-4 1772 ax-5 1869 ax-6 1928 ax-7 1964 ax-8 2050 ax-9 2057 ax-10 2077 ax-11 2091 ax-12 2104 ax-13 2299 ax-ext 2745 ax-sep 5054 ax-nul 5061 ax-pow 5113 ax-pr 5180 ax-un 7273 ax-cnex 10383 ax-resscn 10384 ax-1cn 10385 ax-icn 10386 ax-addcl 10387 ax-addrcl 10388 ax-mulcl 10389 ax-mulrcl 10390 ax-mulcom 10391 ax-addass 10392 ax-mulass 10393 ax-distr 10394 ax-i2m1 10395 ax-1ne0 10396 ax-1rid 10397 ax-rnegex 10398 ax-rrecex 10399 ax-cnre 10400 ax-pre-lttri 10401 ax-pre-lttrn 10402 ax-pre-ltadd 10403 ax-pre-mulgt0 10404 |
This theorem depends on definitions: df-bi 199 df-an 388 df-or 834 df-3or 1069 df-3an 1070 df-tru 1510 df-ex 1743 df-nf 1747 df-sb 2014 df-mo 2544 df-eu 2580 df-clab 2754 df-cleq 2765 df-clel 2840 df-nfc 2912 df-ne 2962 df-nel 3068 df-ral 3087 df-rex 3088 df-reu 3089 df-rmo 3090 df-rab 3091 df-v 3411 df-sbc 3678 df-csb 3783 df-dif 3828 df-un 3830 df-in 3832 df-ss 3839 df-pss 3841 df-nul 4174 df-if 4345 df-pw 4418 df-sn 4436 df-pr 4438 df-tp 4440 df-op 4442 df-uni 4707 df-iun 4788 df-br 4924 df-opab 4986 df-mpt 5003 df-tr 5025 df-id 5305 df-eprel 5310 df-po 5319 df-so 5320 df-fr 5359 df-we 5361 df-xp 5406 df-rel 5407 df-cnv 5408 df-co 5409 df-dm 5410 df-rn 5411 df-res 5412 df-ima 5413 df-pred 5980 df-ord 6026 df-on 6027 df-lim 6028 df-suc 6029 df-iota 6146 df-fun 6184 df-fn 6185 df-f 6186 df-f1 6187 df-fo 6188 df-f1o 6189 df-fv 6190 df-riota 6931 df-ov 6973 df-oprab 6974 df-mpo 6975 df-om 7391 df-wrecs 7743 df-recs 7805 df-rdg 7843 df-er 8081 df-en 8299 df-dom 8300 df-sdom 8301 df-pnf 10468 df-mnf 10469 df-xr 10470 df-ltxr 10471 df-le 10472 df-sub 10664 df-neg 10665 df-div 11091 df-nn 11432 df-2 11496 df-n0 11701 df-z 11787 df-uz 12052 df-odd 43100 |
This theorem is referenced by: (None) |
Copyright terms: Public domain | W3C validator |