![]() |
Intuitionistic Logic Explorer |
< Previous
Next >
Nearby theorems |
|
Mirrors > Home > ILE Home > Th. List > ltneg | GIF version |
Description: Negative of both sides of 'less than'. Theorem I.23 of [Apostol] p. 20. (Contributed by NM, 27-Aug-1999.) (Proof shortened by Mario Carneiro, 27-May-2016.) |
Ref | Expression |
---|---|
ltneg | ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 < 𝐵 ↔ -𝐵 < -𝐴)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 0re 7585 | . . 3 ⊢ 0 ∈ ℝ | |
2 | ltsub2 8034 | . . 3 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 0 ∈ ℝ) → (𝐴 < 𝐵 ↔ (0 − 𝐵) < (0 − 𝐴))) | |
3 | 1, 2 | mp3an3 1269 | . 2 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 < 𝐵 ↔ (0 − 𝐵) < (0 − 𝐴))) |
4 | df-neg 7753 | . . 3 ⊢ -𝐵 = (0 − 𝐵) | |
5 | df-neg 7753 | . . 3 ⊢ -𝐴 = (0 − 𝐴) | |
6 | 4, 5 | breq12i 3876 | . 2 ⊢ (-𝐵 < -𝐴 ↔ (0 − 𝐵) < (0 − 𝐴)) |
7 | 3, 6 | syl6bbr 197 | 1 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 < 𝐵 ↔ -𝐵 < -𝐴)) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 103 ↔ wb 104 ∈ wcel 1445 class class class wbr 3867 (class class class)co 5690 ℝcr 7446 0cc0 7447 < clt 7619 − cmin 7750 -cneg 7751 |
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 582 ax-in2 583 ax-io 668 ax-5 1388 ax-7 1389 ax-gen 1390 ax-ie1 1434 ax-ie2 1435 ax-8 1447 ax-10 1448 ax-11 1449 ax-i12 1450 ax-bndl 1451 ax-4 1452 ax-13 1456 ax-14 1457 ax-17 1471 ax-i9 1475 ax-ial 1479 ax-i5r 1480 ax-ext 2077 ax-sep 3978 ax-pow 4030 ax-pr 4060 ax-un 4284 ax-setind 4381 ax-cnex 7533 ax-resscn 7534 ax-1cn 7535 ax-1re 7536 ax-icn 7537 ax-addcl 7538 ax-addrcl 7539 ax-mulcl 7540 ax-addcom 7542 ax-addass 7544 ax-distr 7546 ax-i2m1 7547 ax-0id 7550 ax-rnegex 7551 ax-cnre 7553 ax-pre-ltadd 7558 |
This theorem depends on definitions: df-bi 116 df-3an 929 df-tru 1299 df-fal 1302 df-nf 1402 df-sb 1700 df-eu 1958 df-mo 1959 df-clab 2082 df-cleq 2088 df-clel 2091 df-nfc 2224 df-ne 2263 df-nel 2358 df-ral 2375 df-rex 2376 df-reu 2377 df-rab 2379 df-v 2635 df-sbc 2855 df-dif 3015 df-un 3017 df-in 3019 df-ss 3026 df-pw 3451 df-sn 3472 df-pr 3473 df-op 3475 df-uni 3676 df-br 3868 df-opab 3922 df-id 4144 df-xp 4473 df-rel 4474 df-cnv 4475 df-co 4476 df-dm 4477 df-iota 5014 df-fun 5051 df-fv 5057 df-riota 5646 df-ov 5693 df-oprab 5694 df-mpt2 5695 df-pnf 7621 df-mnf 7622 df-ltxr 7624 df-sub 7752 df-neg 7753 |
This theorem is referenced by: ltnegcon1 8038 ltnegcon2 8039 lt0neg1 8043 lt0neg2 8044 eqord2 8059 ltnegi 8068 ltnegd 8097 reapneg 8171 negiso 8513 xltnegi 9401 iooneg 9554 |
Copyright terms: Public domain | W3C validator |