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Mirrors > Home > ILE Home > Th. List > 2zsupmax | GIF version |
Description: Two ways to express the maximum of two integers. Because order of integers is decidable, we have more flexibility than for real numbers. (Contributed by Jim Kingdon, 22-Jan-2023.) |
Ref | Expression |
---|---|
2zsupmax | ⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) → sup({𝐴, 𝐵}, ℝ, < ) = if(𝐴 ≤ 𝐵, 𝐵, 𝐴)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simpr 109 | . . . 4 ⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) ∧ 𝐴 ≤ 𝐵) → 𝐴 ≤ 𝐵) | |
2 | zre 8808 | . . . . . 6 ⊢ (𝐴 ∈ ℤ → 𝐴 ∈ ℝ) | |
3 | 2 | adantr 271 | . . . . 5 ⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) → 𝐴 ∈ ℝ) |
4 | zre 8808 | . . . . . . 7 ⊢ (𝐵 ∈ ℤ → 𝐵 ∈ ℝ) | |
5 | 4 | adantl 272 | . . . . . 6 ⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) → 𝐵 ∈ ℝ) |
6 | 5 | adantr 271 | . . . . 5 ⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) ∧ 𝐴 ≤ 𝐵) → 𝐵 ∈ ℝ) |
7 | maxleb 10703 | . . . . 5 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 ≤ 𝐵 ↔ sup({𝐴, 𝐵}, ℝ, < ) = 𝐵)) | |
8 | 3, 6, 7 | syl2an2r 563 | . . . 4 ⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) ∧ 𝐴 ≤ 𝐵) → (𝐴 ≤ 𝐵 ↔ sup({𝐴, 𝐵}, ℝ, < ) = 𝐵)) |
9 | 1, 8 | mpbid 146 | . . 3 ⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) ∧ 𝐴 ≤ 𝐵) → sup({𝐴, 𝐵}, ℝ, < ) = 𝐵) |
10 | 1 | iftrued 3404 | . . 3 ⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) ∧ 𝐴 ≤ 𝐵) → if(𝐴 ≤ 𝐵, 𝐵, 𝐴) = 𝐵) |
11 | 9, 10 | eqtr4d 2124 | . 2 ⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) ∧ 𝐴 ≤ 𝐵) → sup({𝐴, 𝐵}, ℝ, < ) = if(𝐴 ≤ 𝐵, 𝐵, 𝐴)) |
12 | maxcom 10690 | . . . 4 ⊢ sup({𝐵, 𝐴}, ℝ, < ) = sup({𝐴, 𝐵}, ℝ, < ) | |
13 | 5 | adantr 271 | . . . . . 6 ⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) ∧ ¬ 𝐴 ≤ 𝐵) → 𝐵 ∈ ℝ) |
14 | 3 | adantr 271 | . . . . . 6 ⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) ∧ ¬ 𝐴 ≤ 𝐵) → 𝐴 ∈ ℝ) |
15 | zltnle 8850 | . . . . . . . 8 ⊢ ((𝐵 ∈ ℤ ∧ 𝐴 ∈ ℤ) → (𝐵 < 𝐴 ↔ ¬ 𝐴 ≤ 𝐵)) | |
16 | 15 | ancoms 265 | . . . . . . 7 ⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) → (𝐵 < 𝐴 ↔ ¬ 𝐴 ≤ 𝐵)) |
17 | 16 | biimpar 292 | . . . . . 6 ⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) ∧ ¬ 𝐴 ≤ 𝐵) → 𝐵 < 𝐴) |
18 | 13, 14, 17 | ltled 7656 | . . . . 5 ⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) ∧ ¬ 𝐴 ≤ 𝐵) → 𝐵 ≤ 𝐴) |
19 | maxleb 10703 | . . . . . 6 ⊢ ((𝐵 ∈ ℝ ∧ 𝐴 ∈ ℝ) → (𝐵 ≤ 𝐴 ↔ sup({𝐵, 𝐴}, ℝ, < ) = 𝐴)) | |
20 | 5, 14, 19 | syl2an2r 563 | . . . . 5 ⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) ∧ ¬ 𝐴 ≤ 𝐵) → (𝐵 ≤ 𝐴 ↔ sup({𝐵, 𝐴}, ℝ, < ) = 𝐴)) |
21 | 18, 20 | mpbid 146 | . . . 4 ⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) ∧ ¬ 𝐴 ≤ 𝐵) → sup({𝐵, 𝐴}, ℝ, < ) = 𝐴) |
22 | 12, 21 | syl5eqr 2135 | . . 3 ⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) ∧ ¬ 𝐴 ≤ 𝐵) → sup({𝐴, 𝐵}, ℝ, < ) = 𝐴) |
23 | simpr 109 | . . . 4 ⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) ∧ ¬ 𝐴 ≤ 𝐵) → ¬ 𝐴 ≤ 𝐵) | |
24 | 23 | iffalsed 3407 | . . 3 ⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) ∧ ¬ 𝐴 ≤ 𝐵) → if(𝐴 ≤ 𝐵, 𝐵, 𝐴) = 𝐴) |
25 | 22, 24 | eqtr4d 2124 | . 2 ⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) ∧ ¬ 𝐴 ≤ 𝐵) → sup({𝐴, 𝐵}, ℝ, < ) = if(𝐴 ≤ 𝐵, 𝐵, 𝐴)) |
26 | zdcle 8877 | . . 3 ⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) → DECID 𝐴 ≤ 𝐵) | |
27 | exmiddc 783 | . . 3 ⊢ (DECID 𝐴 ≤ 𝐵 → (𝐴 ≤ 𝐵 ∨ ¬ 𝐴 ≤ 𝐵)) | |
28 | 26, 27 | syl 14 | . 2 ⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) → (𝐴 ≤ 𝐵 ∨ ¬ 𝐴 ≤ 𝐵)) |
29 | 11, 25, 28 | mpjaodan 748 | 1 ⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ) → sup({𝐴, 𝐵}, ℝ, < ) = if(𝐴 ≤ 𝐵, 𝐵, 𝐴)) |
Colors of variables: wff set class |
Syntax hints: ¬ wn 3 → wi 4 ∧ wa 103 ↔ wb 104 ∨ wo 665 DECID wdc 781 = wceq 1290 ∈ wcel 1439 ifcif 3397 {cpr 3451 class class class wbr 3851 supcsup 6731 ℝcr 7403 < clt 7576 ≤ cle 7577 ℤcz 8804 |
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-coll 3960 ax-sep 3963 ax-nul 3971 ax-pow 4015 ax-pr 4045 ax-un 4269 ax-setind 4366 ax-iinf 4416 ax-cnex 7490 ax-resscn 7491 ax-1cn 7492 ax-1re 7493 ax-icn 7494 ax-addcl 7495 ax-addrcl 7496 ax-mulcl 7497 ax-mulrcl 7498 ax-addcom 7499 ax-mulcom 7500 ax-addass 7501 ax-mulass 7502 ax-distr 7503 ax-i2m1 7504 ax-0lt1 7505 ax-1rid 7506 ax-0id 7507 ax-rnegex 7508 ax-precex 7509 ax-cnre 7510 ax-pre-ltirr 7511 ax-pre-ltwlin 7512 ax-pre-lttrn 7513 ax-pre-apti 7514 ax-pre-ltadd 7515 ax-pre-mulgt0 7516 ax-pre-mulext 7517 ax-arch 7518 ax-caucvg 7519 |
This theorem depends on definitions: df-bi 116 df-dc 782 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 2622 df-sbc 2842 df-csb 2935 df-dif 3002 df-un 3004 df-in 3006 df-ss 3013 df-nul 3288 df-if 3398 df-pw 3435 df-sn 3456 df-pr 3457 df-op 3459 df-uni 3660 df-int 3695 df-iun 3738 df-br 3852 df-opab 3906 df-mpt 3907 df-tr 3943 df-id 4129 df-po 4132 df-iso 4133 df-iord 4202 df-on 4204 df-ilim 4205 df-suc 4207 df-iom 4419 df-xp 4457 df-rel 4458 df-cnv 4459 df-co 4460 df-dm 4461 df-rn 4462 df-res 4463 df-ima 4464 df-iota 4993 df-fun 5030 df-fn 5031 df-f 5032 df-f1 5033 df-fo 5034 df-f1o 5035 df-fv 5036 df-riota 5622 df-ov 5669 df-oprab 5670 df-mpt2 5671 df-1st 5925 df-2nd 5926 df-recs 6084 df-frec 6170 df-sup 6733 df-pnf 7578 df-mnf 7579 df-xr 7580 df-ltxr 7581 df-le 7582 df-sub 7709 df-neg 7710 df-reap 8106 df-ap 8113 df-div 8194 df-inn 8477 df-2 8535 df-3 8536 df-4 8537 df-n0 8728 df-z 8805 df-uz 9074 df-rp 9189 df-iseq 9907 df-seq3 9908 df-exp 10009 df-cj 10330 df-re 10331 df-im 10332 df-rsqrt 10485 df-abs 10486 |
This theorem is referenced by: (None) |
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