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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 12311 | . . 3 ⊢ ((𝑁 ∈ ℕ0 ∧ 𝑁 ≠ 0 ∧ 𝑁 ≠ 1) → 2 ≤ 𝑁) | |
2 | 1 | 3expib 1121 | . 2 ⊢ (𝑁 ∈ ℕ0 → ((𝑁 ≠ 0 ∧ 𝑁 ≠ 1) → 2 ≤ 𝑁)) |
3 | ianor 979 | . . . 4 ⊢ (¬ (𝑁 ≠ 0 ∧ 𝑁 ≠ 1) ↔ (¬ 𝑁 ≠ 0 ∨ ¬ 𝑁 ≠ 1)) | |
4 | nne 2949 | . . . . 5 ⊢ (¬ 𝑁 ≠ 0 ↔ 𝑁 = 0) | |
5 | nne 2949 | . . . . 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 12087 | . . . . . . . . 9 ⊢ 0 < 2 | |
9 | breq1 5082 | . . . . . . . . 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 12155 | . . . . . . . . 9 ⊢ 1 < 2 | |
13 | breq1 5082 | . . . . . . . . 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 854 | . . . . . 6 ⊢ ((𝑁 = 0 ∨ 𝑁 = 1) → (𝑁 ∈ ℕ0 → 𝑁 < 2)) |
17 | 16 | impcom 408 | . . . . 5 ⊢ ((𝑁 ∈ ℕ0 ∧ (𝑁 = 0 ∨ 𝑁 = 1)) → 𝑁 < 2) |
18 | nn0re 12253 | . . . . . . . 8 ⊢ (𝑁 ∈ ℕ0 → 𝑁 ∈ ℝ) | |
19 | 2re 12058 | . . . . . . . 8 ⊢ 2 ∈ ℝ | |
20 | 18, 19 | jctir 521 | . . . . . . 7 ⊢ (𝑁 ∈ ℕ0 → (𝑁 ∈ ℝ ∧ 2 ∈ ℝ)) |
21 | 20 | adantr 481 | . . . . . 6 ⊢ ((𝑁 ∈ ℕ0 ∧ (𝑁 = 0 ∨ 𝑁 = 1)) → (𝑁 ∈ ℝ ∧ 2 ∈ ℝ)) |
22 | ltnle 11065 | . . . . . 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 413 | . . 3 ⊢ (𝑁 ∈ ℕ0 → ((𝑁 = 0 ∨ 𝑁 = 1) → ¬ 2 ≤ 𝑁)) |
26 | 7, 25 | syl5bi 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 396 ∨ wo 844 = wceq 1542 ∈ wcel 2110 ≠ wne 2945 class class class wbr 5079 ℝcr 10881 0cc0 10882 1c1 10883 < clt 11020 ≤ cle 11021 2c2 12039 ℕ0cn0 12244 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1802 ax-4 1816 ax-5 1917 ax-6 1975 ax-7 2015 ax-8 2112 ax-9 2120 ax-10 2141 ax-11 2158 ax-12 2175 ax-ext 2711 ax-sep 5227 ax-nul 5234 ax-pow 5292 ax-pr 5356 ax-un 7583 ax-resscn 10939 ax-1cn 10940 ax-icn 10941 ax-addcl 10942 ax-addrcl 10943 ax-mulcl 10944 ax-mulrcl 10945 ax-mulcom 10946 ax-addass 10947 ax-mulass 10948 ax-distr 10949 ax-i2m1 10950 ax-1ne0 10951 ax-1rid 10952 ax-rnegex 10953 ax-rrecex 10954 ax-cnre 10955 ax-pre-lttri 10956 ax-pre-lttrn 10957 ax-pre-ltadd 10958 ax-pre-mulgt0 10959 |
This theorem depends on definitions: df-bi 206 df-an 397 df-or 845 df-3or 1087 df-3an 1088 df-tru 1545 df-fal 1555 df-ex 1787 df-nf 1791 df-sb 2072 df-mo 2542 df-eu 2571 df-clab 2718 df-cleq 2732 df-clel 2818 df-nfc 2891 df-ne 2946 df-nel 3052 df-ral 3071 df-rex 3072 df-reu 3073 df-rab 3075 df-v 3433 df-sbc 3721 df-csb 3838 df-dif 3895 df-un 3897 df-in 3899 df-ss 3909 df-pss 3911 df-nul 4263 df-if 4466 df-pw 4541 df-sn 4568 df-pr 4570 df-op 4574 df-uni 4846 df-iun 4932 df-br 5080 df-opab 5142 df-mpt 5163 df-tr 5197 df-id 5490 df-eprel 5496 df-po 5504 df-so 5505 df-fr 5545 df-we 5547 df-xp 5596 df-rel 5597 df-cnv 5598 df-co 5599 df-dm 5600 df-rn 5601 df-res 5602 df-ima 5603 df-pred 6201 df-ord 6268 df-on 6269 df-lim 6270 df-suc 6271 df-iota 6390 df-fun 6434 df-fn 6435 df-f 6436 df-f1 6437 df-fo 6438 df-f1o 6439 df-fv 6440 df-riota 7229 df-ov 7275 df-oprab 7276 df-mpo 7277 df-om 7708 df-2nd 7826 df-frecs 8089 df-wrecs 8120 df-recs 8194 df-rdg 8233 df-er 8490 df-en 8726 df-dom 8727 df-sdom 8728 df-pnf 11022 df-mnf 11023 df-xr 11024 df-ltxr 11025 df-le 11026 df-sub 11218 df-neg 11219 df-nn 11985 df-2 12047 df-n0 12245 |
This theorem is referenced by: xnn0n0n1ge2b 12878 |
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