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Mirrors > Home > ILE Home > Th. List > nngt1ne1 | GIF version |
Description: A positive integer is greater than one iff it is not equal to one. (Contributed by NM, 7-Oct-2004.) |
Ref | Expression |
---|---|
nngt1ne1 | ⊢ (𝐴 ∈ ℕ → (1 < 𝐴 ↔ 𝐴 ≠ 1)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 1re 7958 | . . 3 ⊢ 1 ∈ ℝ | |
2 | ltne 8044 | . . 3 ⊢ ((1 ∈ ℝ ∧ 1 < 𝐴) → 𝐴 ≠ 1) | |
3 | 1, 2 | mpan 424 | . 2 ⊢ (1 < 𝐴 → 𝐴 ≠ 1) |
4 | df-ne 2348 | . . 3 ⊢ (𝐴 ≠ 1 ↔ ¬ 𝐴 = 1) | |
5 | nn1gt1 8955 | . . . 4 ⊢ (𝐴 ∈ ℕ → (𝐴 = 1 ∨ 1 < 𝐴)) | |
6 | 5 | ord 724 | . . 3 ⊢ (𝐴 ∈ ℕ → (¬ 𝐴 = 1 → 1 < 𝐴)) |
7 | 4, 6 | biimtrid 152 | . 2 ⊢ (𝐴 ∈ ℕ → (𝐴 ≠ 1 → 1 < 𝐴)) |
8 | 3, 7 | impbid2 143 | 1 ⊢ (𝐴 ∈ ℕ → (1 < 𝐴 ↔ 𝐴 ≠ 1)) |
Colors of variables: wff set class |
Syntax hints: ¬ wn 3 → wi 4 ↔ wb 105 = wceq 1353 ∈ wcel 2148 ≠ wne 2347 class class class wbr 4005 ℝcr 7812 1c1 7814 < clt 7994 ℕcn 8921 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-in1 614 ax-in2 615 ax-io 709 ax-5 1447 ax-7 1448 ax-gen 1449 ax-ie1 1493 ax-ie2 1494 ax-8 1504 ax-10 1505 ax-11 1506 ax-i12 1507 ax-bndl 1509 ax-4 1510 ax-17 1526 ax-i9 1530 ax-ial 1534 ax-i5r 1535 ax-13 2150 ax-14 2151 ax-ext 2159 ax-sep 4123 ax-pow 4176 ax-pr 4211 ax-un 4435 ax-setind 4538 ax-cnex 7904 ax-resscn 7905 ax-1cn 7906 ax-1re 7907 ax-icn 7908 ax-addcl 7909 ax-addrcl 7910 ax-mulcl 7911 ax-addcom 7913 ax-addass 7915 ax-i2m1 7918 ax-0lt1 7919 ax-0id 7921 ax-rnegex 7922 ax-pre-ltirr 7925 ax-pre-ltwlin 7926 ax-pre-lttrn 7927 ax-pre-ltadd 7929 |
This theorem depends on definitions: df-bi 117 df-3an 980 df-tru 1356 df-fal 1359 df-nf 1461 df-sb 1763 df-eu 2029 df-mo 2030 df-clab 2164 df-cleq 2170 df-clel 2173 df-nfc 2308 df-ne 2348 df-nel 2443 df-ral 2460 df-rex 2461 df-rab 2464 df-v 2741 df-dif 3133 df-un 3135 df-in 3137 df-ss 3144 df-pw 3579 df-sn 3600 df-pr 3601 df-op 3603 df-uni 3812 df-int 3847 df-br 4006 df-opab 4067 df-xp 4634 df-cnv 4636 df-iota 5180 df-fv 5226 df-ov 5880 df-pnf 7996 df-mnf 7997 df-xr 7998 df-ltxr 7999 df-le 8000 df-inn 8922 |
This theorem is referenced by: prime 9354 eluz2b3 9606 ncoprmgcdne1b 12091 ncoprmgcdgt1b 12092 |
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