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Mirrors > Home > ILE Home > Th. List > qavgle | GIF version |
Description: The average of two rational numbers is less than or equal to at least one of them. (Contributed by Jim Kingdon, 3-Nov-2021.) |
Ref | Expression |
---|---|
qavgle | ⊢ ((𝐴 ∈ ℚ ∧ 𝐵 ∈ ℚ) → (((𝐴 + 𝐵) / 2) ≤ 𝐴 ∨ ((𝐴 + 𝐵) / 2) ≤ 𝐵)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | qletric 9718 | . . 3 ⊢ ((𝐴 ∈ ℚ ∧ 𝐵 ∈ ℚ) → (𝐴 ≤ 𝐵 ∨ 𝐵 ≤ 𝐴)) | |
2 | 1 | orcomd 684 | . 2 ⊢ ((𝐴 ∈ ℚ ∧ 𝐵 ∈ ℚ) → (𝐵 ≤ 𝐴 ∨ 𝐴 ≤ 𝐵)) |
3 | qre 9173 | . . . . . 6 ⊢ (𝐵 ∈ ℚ → 𝐵 ∈ ℝ) | |
4 | 3 | adantl 272 | . . . . 5 ⊢ ((𝐴 ∈ ℚ ∧ 𝐵 ∈ ℚ) → 𝐵 ∈ ℝ) |
5 | qre 9173 | . . . . . 6 ⊢ (𝐴 ∈ ℚ → 𝐴 ∈ ℝ) | |
6 | 5 | adantr 271 | . . . . 5 ⊢ ((𝐴 ∈ ℚ ∧ 𝐵 ∈ ℚ) → 𝐴 ∈ ℝ) |
7 | avgle2 8720 | . . . . 5 ⊢ ((𝐵 ∈ ℝ ∧ 𝐴 ∈ ℝ) → (𝐵 ≤ 𝐴 ↔ ((𝐵 + 𝐴) / 2) ≤ 𝐴)) | |
8 | 4, 6, 7 | syl2anc 404 | . . . 4 ⊢ ((𝐴 ∈ ℚ ∧ 𝐵 ∈ ℚ) → (𝐵 ≤ 𝐴 ↔ ((𝐵 + 𝐴) / 2) ≤ 𝐴)) |
9 | qcn 9182 | . . . . . . . 8 ⊢ (𝐴 ∈ ℚ → 𝐴 ∈ ℂ) | |
10 | 9 | adantr 271 | . . . . . . 7 ⊢ ((𝐴 ∈ ℚ ∧ 𝐵 ∈ ℚ) → 𝐴 ∈ ℂ) |
11 | qcn 9182 | . . . . . . . 8 ⊢ (𝐵 ∈ ℚ → 𝐵 ∈ ℂ) | |
12 | 11 | adantl 272 | . . . . . . 7 ⊢ ((𝐴 ∈ ℚ ∧ 𝐵 ∈ ℚ) → 𝐵 ∈ ℂ) |
13 | 10, 12 | addcomd 7696 | . . . . . 6 ⊢ ((𝐴 ∈ ℚ ∧ 𝐵 ∈ ℚ) → (𝐴 + 𝐵) = (𝐵 + 𝐴)) |
14 | 13 | oveq1d 5683 | . . . . 5 ⊢ ((𝐴 ∈ ℚ ∧ 𝐵 ∈ ℚ) → ((𝐴 + 𝐵) / 2) = ((𝐵 + 𝐴) / 2)) |
15 | 14 | breq1d 3863 | . . . 4 ⊢ ((𝐴 ∈ ℚ ∧ 𝐵 ∈ ℚ) → (((𝐴 + 𝐵) / 2) ≤ 𝐴 ↔ ((𝐵 + 𝐴) / 2) ≤ 𝐴)) |
16 | 8, 15 | bitr4d 190 | . . 3 ⊢ ((𝐴 ∈ ℚ ∧ 𝐵 ∈ ℚ) → (𝐵 ≤ 𝐴 ↔ ((𝐴 + 𝐵) / 2) ≤ 𝐴)) |
17 | avgle2 8720 | . . . 4 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 ≤ 𝐵 ↔ ((𝐴 + 𝐵) / 2) ≤ 𝐵)) | |
18 | 6, 4, 17 | syl2anc 404 | . . 3 ⊢ ((𝐴 ∈ ℚ ∧ 𝐵 ∈ ℚ) → (𝐴 ≤ 𝐵 ↔ ((𝐴 + 𝐵) / 2) ≤ 𝐵)) |
19 | 16, 18 | orbi12d 743 | . 2 ⊢ ((𝐴 ∈ ℚ ∧ 𝐵 ∈ ℚ) → ((𝐵 ≤ 𝐴 ∨ 𝐴 ≤ 𝐵) ↔ (((𝐴 + 𝐵) / 2) ≤ 𝐴 ∨ ((𝐴 + 𝐵) / 2) ≤ 𝐵))) |
20 | 2, 19 | mpbid 146 | 1 ⊢ ((𝐴 ∈ ℚ ∧ 𝐵 ∈ ℚ) → (((𝐴 + 𝐵) / 2) ≤ 𝐴 ∨ ((𝐴 + 𝐵) / 2) ≤ 𝐵)) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 103 ↔ wb 104 ∨ wo 665 ∈ wcel 1439 class class class wbr 3853 (class class class)co 5668 ℂcc 7411 ℝcr 7412 + caddc 7416 ≤ cle 7586 / cdiv 8202 2c2 8536 ℚcq 9167 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 105 ax-ia2 106 ax-ia3 107 ax-in1 580 ax-in2 581 ax-io 666 ax-5 1382 ax-7 1383 ax-gen 1384 ax-ie1 1428 ax-ie2 1429 ax-8 1441 ax-10 1442 ax-11 1443 ax-i12 1444 ax-bndl 1445 ax-4 1446 ax-13 1450 ax-14 1451 ax-17 1465 ax-i9 1469 ax-ial 1473 ax-i5r 1474 ax-ext 2071 ax-sep 3965 ax-pow 4017 ax-pr 4047 ax-un 4271 ax-setind 4368 ax-cnex 7499 ax-resscn 7500 ax-1cn 7501 ax-1re 7502 ax-icn 7503 ax-addcl 7504 ax-addrcl 7505 ax-mulcl 7506 ax-mulrcl 7507 ax-addcom 7508 ax-mulcom 7509 ax-addass 7510 ax-mulass 7511 ax-distr 7512 ax-i2m1 7513 ax-0lt1 7514 ax-1rid 7515 ax-0id 7516 ax-rnegex 7517 ax-precex 7518 ax-cnre 7519 ax-pre-ltirr 7520 ax-pre-ltwlin 7521 ax-pre-lttrn 7522 ax-pre-apti 7523 ax-pre-ltadd 7524 ax-pre-mulgt0 7525 ax-pre-mulext 7526 |
This theorem depends on definitions: df-bi 116 df-3or 926 df-3an 927 df-tru 1293 df-fal 1296 df-nf 1396 df-sb 1694 df-eu 1952 df-mo 1953 df-clab 2076 df-cleq 2082 df-clel 2085 df-nfc 2218 df-ne 2257 df-nel 2352 df-ral 2365 df-rex 2366 df-reu 2367 df-rmo 2368 df-rab 2369 df-v 2624 df-sbc 2844 df-csb 2937 df-dif 3004 df-un 3006 df-in 3008 df-ss 3015 df-pw 3437 df-sn 3458 df-pr 3459 df-op 3461 df-uni 3662 df-int 3697 df-iun 3740 df-br 3854 df-opab 3908 df-mpt 3909 df-id 4131 df-po 4134 df-iso 4135 df-xp 4460 df-rel 4461 df-cnv 4462 df-co 4463 df-dm 4464 df-rn 4465 df-res 4466 df-ima 4467 df-iota 4995 df-fun 5032 df-fn 5033 df-f 5034 df-fv 5038 df-riota 5624 df-ov 5671 df-oprab 5672 df-mpt2 5673 df-1st 5927 df-2nd 5928 df-pnf 7587 df-mnf 7588 df-xr 7589 df-ltxr 7590 df-le 7591 df-sub 7718 df-neg 7719 df-reap 8115 df-ap 8122 df-div 8203 df-inn 8486 df-2 8544 df-n0 8737 df-z 8814 df-q 9168 df-rp 9198 |
This theorem is referenced by: facavg 10217 |
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