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Mirrors > Home > MPE Home > Th. List > nn0n0n1ge2b | Structured version Visualization version GIF version |
Description: A nonnegative integer is neither 0 nor 1 if and only if it is greater than or equal to 2. (Contributed by Alexander van der Vekens, 17-Jan-2018.) |
Ref | Expression |
---|---|
nn0n0n1ge2b | ⊢ (𝑁 ∈ ℕ0 → ((𝑁 ≠ 0 ∧ 𝑁 ≠ 1) ↔ 2 ≤ 𝑁)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nn0n0n1ge2 12591 | . . 3 ⊢ ((𝑁 ∈ ℕ0 ∧ 𝑁 ≠ 0 ∧ 𝑁 ≠ 1) → 2 ≤ 𝑁) | |
2 | 1 | 3expib 1119 | . 2 ⊢ (𝑁 ∈ ℕ0 → ((𝑁 ≠ 0 ∧ 𝑁 ≠ 1) → 2 ≤ 𝑁)) |
3 | ianor 979 | . . . 4 ⊢ (¬ (𝑁 ≠ 0 ∧ 𝑁 ≠ 1) ↔ (¬ 𝑁 ≠ 0 ∨ ¬ 𝑁 ≠ 1)) | |
4 | nne 2934 | . . . . 5 ⊢ (¬ 𝑁 ≠ 0 ↔ 𝑁 = 0) | |
5 | nne 2934 | . . . . 5 ⊢ (¬ 𝑁 ≠ 1 ↔ 𝑁 = 1) | |
6 | 4, 5 | orbi12i 912 | . . . 4 ⊢ ((¬ 𝑁 ≠ 0 ∨ ¬ 𝑁 ≠ 1) ↔ (𝑁 = 0 ∨ 𝑁 = 1)) |
7 | 3, 6 | bitri 274 | . . 3 ⊢ (¬ (𝑁 ≠ 0 ∧ 𝑁 ≠ 1) ↔ (𝑁 = 0 ∨ 𝑁 = 1)) |
8 | 2pos 12367 | . . . . . . . . 9 ⊢ 0 < 2 | |
9 | breq1 5156 | . . . . . . . . 9 ⊢ (𝑁 = 0 → (𝑁 < 2 ↔ 0 < 2)) | |
10 | 8, 9 | mpbiri 257 | . . . . . . . 8 ⊢ (𝑁 = 0 → 𝑁 < 2) |
11 | 10 | a1d 25 | . . . . . . 7 ⊢ (𝑁 = 0 → (𝑁 ∈ ℕ0 → 𝑁 < 2)) |
12 | 1lt2 12435 | . . . . . . . . 9 ⊢ 1 < 2 | |
13 | breq1 5156 | . . . . . . . . 9 ⊢ (𝑁 = 1 → (𝑁 < 2 ↔ 1 < 2)) | |
14 | 12, 13 | mpbiri 257 | . . . . . . . 8 ⊢ (𝑁 = 1 → 𝑁 < 2) |
15 | 14 | a1d 25 | . . . . . . 7 ⊢ (𝑁 = 1 → (𝑁 ∈ ℕ0 → 𝑁 < 2)) |
16 | 11, 15 | jaoi 855 | . . . . . 6 ⊢ ((𝑁 = 0 ∨ 𝑁 = 1) → (𝑁 ∈ ℕ0 → 𝑁 < 2)) |
17 | 16 | impcom 406 | . . . . 5 ⊢ ((𝑁 ∈ ℕ0 ∧ (𝑁 = 0 ∨ 𝑁 = 1)) → 𝑁 < 2) |
18 | nn0re 12533 | . . . . . . . 8 ⊢ (𝑁 ∈ ℕ0 → 𝑁 ∈ ℝ) | |
19 | 2re 12338 | . . . . . . . 8 ⊢ 2 ∈ ℝ | |
20 | 18, 19 | jctir 519 | . . . . . . 7 ⊢ (𝑁 ∈ ℕ0 → (𝑁 ∈ ℝ ∧ 2 ∈ ℝ)) |
21 | 20 | adantr 479 | . . . . . 6 ⊢ ((𝑁 ∈ ℕ0 ∧ (𝑁 = 0 ∨ 𝑁 = 1)) → (𝑁 ∈ ℝ ∧ 2 ∈ ℝ)) |
22 | ltnle 11343 | . . . . . 6 ⊢ ((𝑁 ∈ ℝ ∧ 2 ∈ ℝ) → (𝑁 < 2 ↔ ¬ 2 ≤ 𝑁)) | |
23 | 21, 22 | syl 17 | . . . . 5 ⊢ ((𝑁 ∈ ℕ0 ∧ (𝑁 = 0 ∨ 𝑁 = 1)) → (𝑁 < 2 ↔ ¬ 2 ≤ 𝑁)) |
24 | 17, 23 | mpbid 231 | . . . 4 ⊢ ((𝑁 ∈ ℕ0 ∧ (𝑁 = 0 ∨ 𝑁 = 1)) → ¬ 2 ≤ 𝑁) |
25 | 24 | ex 411 | . . 3 ⊢ (𝑁 ∈ ℕ0 → ((𝑁 = 0 ∨ 𝑁 = 1) → ¬ 2 ≤ 𝑁)) |
26 | 7, 25 | biimtrid 241 | . 2 ⊢ (𝑁 ∈ ℕ0 → (¬ (𝑁 ≠ 0 ∧ 𝑁 ≠ 1) → ¬ 2 ≤ 𝑁)) |
27 | 2, 26 | impcon4bid 226 | 1 ⊢ (𝑁 ∈ ℕ0 → ((𝑁 ≠ 0 ∧ 𝑁 ≠ 1) ↔ 2 ≤ 𝑁)) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ↔ wb 205 ∧ wa 394 ∨ wo 845 = wceq 1534 ∈ wcel 2099 ≠ wne 2930 class class class wbr 5153 ℝcr 11157 0cc0 11158 1c1 11159 < clt 11298 ≤ cle 11299 2c2 12319 ℕ0cn0 12524 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1790 ax-4 1804 ax-5 1906 ax-6 1964 ax-7 2004 ax-8 2101 ax-9 2109 ax-10 2130 ax-11 2147 ax-12 2167 ax-ext 2697 ax-sep 5304 ax-nul 5311 ax-pow 5369 ax-pr 5433 ax-un 7746 ax-resscn 11215 ax-1cn 11216 ax-icn 11217 ax-addcl 11218 ax-addrcl 11219 ax-mulcl 11220 ax-mulrcl 11221 ax-mulcom 11222 ax-addass 11223 ax-mulass 11224 ax-distr 11225 ax-i2m1 11226 ax-1ne0 11227 ax-1rid 11228 ax-rnegex 11229 ax-rrecex 11230 ax-cnre 11231 ax-pre-lttri 11232 ax-pre-lttrn 11233 ax-pre-ltadd 11234 ax-pre-mulgt0 11235 |
This theorem depends on definitions: df-bi 206 df-an 395 df-or 846 df-3or 1085 df-3an 1086 df-tru 1537 df-fal 1547 df-ex 1775 df-nf 1779 df-sb 2061 df-mo 2529 df-eu 2558 df-clab 2704 df-cleq 2718 df-clel 2803 df-nfc 2878 df-ne 2931 df-nel 3037 df-ral 3052 df-rex 3061 df-reu 3365 df-rab 3420 df-v 3464 df-sbc 3777 df-csb 3893 df-dif 3950 df-un 3952 df-in 3954 df-ss 3964 df-pss 3967 df-nul 4326 df-if 4534 df-pw 4609 df-sn 4634 df-pr 4636 df-op 4640 df-uni 4914 df-iun 5003 df-br 5154 df-opab 5216 df-mpt 5237 df-tr 5271 df-id 5580 df-eprel 5586 df-po 5594 df-so 5595 df-fr 5637 df-we 5639 df-xp 5688 df-rel 5689 df-cnv 5690 df-co 5691 df-dm 5692 df-rn 5693 df-res 5694 df-ima 5695 df-pred 6312 df-ord 6379 df-on 6380 df-lim 6381 df-suc 6382 df-iota 6506 df-fun 6556 df-fn 6557 df-f 6558 df-f1 6559 df-fo 6560 df-f1o 6561 df-fv 6562 df-riota 7380 df-ov 7427 df-oprab 7428 df-mpo 7429 df-om 7877 df-2nd 8004 df-frecs 8296 df-wrecs 8327 df-recs 8401 df-rdg 8440 df-er 8734 df-en 8975 df-dom 8976 df-sdom 8977 df-pnf 11300 df-mnf 11301 df-xr 11302 df-ltxr 11303 df-le 11304 df-sub 11496 df-neg 11497 df-nn 12265 df-2 12327 df-n0 12525 |
This theorem is referenced by: xnn0n0n1ge2b 13165 |
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