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Mirrors > Home > ILE Home > Th. List > le2tri3i | GIF version |
Description: Extended trichotomy law for 'less than or equal to'. (Contributed by NM, 14-Aug-2000.) |
Ref | Expression |
---|---|
lt.1 | ⊢ 𝐴 ∈ ℝ |
lt.2 | ⊢ 𝐵 ∈ ℝ |
lt.3 | ⊢ 𝐶 ∈ ℝ |
Ref | Expression |
---|---|
le2tri3i | ⊢ ((𝐴 ≤ 𝐵 ∧ 𝐵 ≤ 𝐶 ∧ 𝐶 ≤ 𝐴) ↔ (𝐴 = 𝐵 ∧ 𝐵 = 𝐶 ∧ 𝐶 = 𝐴)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | lt.2 | . . . . . 6 ⊢ 𝐵 ∈ ℝ | |
2 | lt.3 | . . . . . 6 ⊢ 𝐶 ∈ ℝ | |
3 | lt.1 | . . . . . 6 ⊢ 𝐴 ∈ ℝ | |
4 | 1, 2, 3 | letri 7590 | . . . . 5 ⊢ ((𝐵 ≤ 𝐶 ∧ 𝐶 ≤ 𝐴) → 𝐵 ≤ 𝐴) |
5 | 3, 1 | letri3i 7581 | . . . . . 6 ⊢ (𝐴 = 𝐵 ↔ (𝐴 ≤ 𝐵 ∧ 𝐵 ≤ 𝐴)) |
6 | 5 | biimpri 131 | . . . . 5 ⊢ ((𝐴 ≤ 𝐵 ∧ 𝐵 ≤ 𝐴) → 𝐴 = 𝐵) |
7 | 4, 6 | sylan2 280 | . . . 4 ⊢ ((𝐴 ≤ 𝐵 ∧ (𝐵 ≤ 𝐶 ∧ 𝐶 ≤ 𝐴)) → 𝐴 = 𝐵) |
8 | 7 | 3impb 1139 | . . 3 ⊢ ((𝐴 ≤ 𝐵 ∧ 𝐵 ≤ 𝐶 ∧ 𝐶 ≤ 𝐴) → 𝐴 = 𝐵) |
9 | 2, 3, 1 | letri 7590 | . . . . . 6 ⊢ ((𝐶 ≤ 𝐴 ∧ 𝐴 ≤ 𝐵) → 𝐶 ≤ 𝐵) |
10 | 1, 2 | letri3i 7581 | . . . . . . 7 ⊢ (𝐵 = 𝐶 ↔ (𝐵 ≤ 𝐶 ∧ 𝐶 ≤ 𝐵)) |
11 | 10 | biimpri 131 | . . . . . 6 ⊢ ((𝐵 ≤ 𝐶 ∧ 𝐶 ≤ 𝐵) → 𝐵 = 𝐶) |
12 | 9, 11 | sylan2 280 | . . . . 5 ⊢ ((𝐵 ≤ 𝐶 ∧ (𝐶 ≤ 𝐴 ∧ 𝐴 ≤ 𝐵)) → 𝐵 = 𝐶) |
13 | 12 | 3impb 1139 | . . . 4 ⊢ ((𝐵 ≤ 𝐶 ∧ 𝐶 ≤ 𝐴 ∧ 𝐴 ≤ 𝐵) → 𝐵 = 𝐶) |
14 | 13 | 3comr 1151 | . . 3 ⊢ ((𝐴 ≤ 𝐵 ∧ 𝐵 ≤ 𝐶 ∧ 𝐶 ≤ 𝐴) → 𝐵 = 𝐶) |
15 | 3, 1, 2 | letri 7590 | . . . . 5 ⊢ ((𝐴 ≤ 𝐵 ∧ 𝐵 ≤ 𝐶) → 𝐴 ≤ 𝐶) |
16 | 3, 2 | letri3i 7581 | . . . . . . 7 ⊢ (𝐴 = 𝐶 ↔ (𝐴 ≤ 𝐶 ∧ 𝐶 ≤ 𝐴)) |
17 | 16 | biimpri 131 | . . . . . 6 ⊢ ((𝐴 ≤ 𝐶 ∧ 𝐶 ≤ 𝐴) → 𝐴 = 𝐶) |
18 | 17 | eqcomd 2093 | . . . . 5 ⊢ ((𝐴 ≤ 𝐶 ∧ 𝐶 ≤ 𝐴) → 𝐶 = 𝐴) |
19 | 15, 18 | sylan 277 | . . . 4 ⊢ (((𝐴 ≤ 𝐵 ∧ 𝐵 ≤ 𝐶) ∧ 𝐶 ≤ 𝐴) → 𝐶 = 𝐴) |
20 | 19 | 3impa 1138 | . . 3 ⊢ ((𝐴 ≤ 𝐵 ∧ 𝐵 ≤ 𝐶 ∧ 𝐶 ≤ 𝐴) → 𝐶 = 𝐴) |
21 | 8, 14, 20 | 3jca 1123 | . 2 ⊢ ((𝐴 ≤ 𝐵 ∧ 𝐵 ≤ 𝐶 ∧ 𝐶 ≤ 𝐴) → (𝐴 = 𝐵 ∧ 𝐵 = 𝐶 ∧ 𝐶 = 𝐴)) |
22 | 3 | eqlei 7576 | . . 3 ⊢ (𝐴 = 𝐵 → 𝐴 ≤ 𝐵) |
23 | 1 | eqlei 7576 | . . 3 ⊢ (𝐵 = 𝐶 → 𝐵 ≤ 𝐶) |
24 | 2 | eqlei 7576 | . . 3 ⊢ (𝐶 = 𝐴 → 𝐶 ≤ 𝐴) |
25 | 22, 23, 24 | 3anim123i 1128 | . 2 ⊢ ((𝐴 = 𝐵 ∧ 𝐵 = 𝐶 ∧ 𝐶 = 𝐴) → (𝐴 ≤ 𝐵 ∧ 𝐵 ≤ 𝐶 ∧ 𝐶 ≤ 𝐴)) |
26 | 21, 25 | impbii 124 | 1 ⊢ ((𝐴 ≤ 𝐵 ∧ 𝐵 ≤ 𝐶 ∧ 𝐶 ≤ 𝐴) ↔ (𝐴 = 𝐵 ∧ 𝐵 = 𝐶 ∧ 𝐶 = 𝐴)) |
Colors of variables: wff set class |
Syntax hints: ∧ wa 102 ↔ wb 103 ∧ w3a 924 = wceq 1289 ∈ wcel 1438 class class class wbr 3845 ℝcr 7347 ≤ cle 7521 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 104 ax-ia2 105 ax-ia3 106 ax-in1 579 ax-in2 580 ax-io 665 ax-5 1381 ax-7 1382 ax-gen 1383 ax-ie1 1427 ax-ie2 1428 ax-8 1440 ax-10 1441 ax-11 1442 ax-i12 1443 ax-bndl 1444 ax-4 1445 ax-13 1449 ax-14 1450 ax-17 1464 ax-i9 1468 ax-ial 1472 ax-i5r 1473 ax-ext 2070 ax-sep 3957 ax-pow 4009 ax-pr 4036 ax-un 4260 ax-setind 4353 ax-cnex 7434 ax-resscn 7435 ax-pre-ltirr 7455 ax-pre-ltwlin 7456 ax-pre-apti 7458 |
This theorem depends on definitions: df-bi 115 df-3an 926 df-tru 1292 df-fal 1295 df-nf 1395 df-sb 1693 df-eu 1951 df-mo 1952 df-clab 2075 df-cleq 2081 df-clel 2084 df-nfc 2217 df-ne 2256 df-nel 2351 df-ral 2364 df-rex 2365 df-rab 2368 df-v 2621 df-dif 3001 df-un 3003 df-in 3005 df-ss 3012 df-pw 3431 df-sn 3452 df-pr 3453 df-op 3455 df-uni 3654 df-br 3846 df-opab 3900 df-xp 4444 df-cnv 4446 df-pnf 7522 df-mnf 7523 df-xr 7524 df-ltxr 7525 df-le 7526 |
This theorem is referenced by: (None) |
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