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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 7992 | . . 3 ⊢ 0 ∈ ℝ | |
2 | ltsub2 8451 | . . 3 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 0 ∈ ℝ) → (𝐴 < 𝐵 ↔ (0 − 𝐵) < (0 − 𝐴))) | |
3 | 1, 2 | mp3an3 1337 | . 2 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 < 𝐵 ↔ (0 − 𝐵) < (0 − 𝐴))) |
4 | df-neg 8166 | . . 3 ⊢ -𝐵 = (0 − 𝐵) | |
5 | df-neg 8166 | . . 3 ⊢ -𝐴 = (0 − 𝐴) | |
6 | 4, 5 | breq12i 4030 | . 2 ⊢ (-𝐵 < -𝐴 ↔ (0 − 𝐵) < (0 − 𝐴)) |
7 | 3, 6 | bitr4di 198 | 1 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 < 𝐵 ↔ -𝐵 < -𝐴)) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 104 ↔ wb 105 ∈ wcel 2160 class class class wbr 4021 (class class class)co 5900 ℝcr 7845 0cc0 7846 < clt 8027 − cmin 8163 -cneg 8164 |
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 615 ax-in2 616 ax-io 710 ax-5 1458 ax-7 1459 ax-gen 1460 ax-ie1 1504 ax-ie2 1505 ax-8 1515 ax-10 1516 ax-11 1517 ax-i12 1518 ax-bndl 1520 ax-4 1521 ax-17 1537 ax-i9 1541 ax-ial 1545 ax-i5r 1546 ax-13 2162 ax-14 2163 ax-ext 2171 ax-sep 4139 ax-pow 4195 ax-pr 4230 ax-un 4454 ax-setind 4557 ax-cnex 7937 ax-resscn 7938 ax-1cn 7939 ax-1re 7940 ax-icn 7941 ax-addcl 7942 ax-addrcl 7943 ax-mulcl 7944 ax-addcom 7946 ax-addass 7948 ax-distr 7950 ax-i2m1 7951 ax-0id 7954 ax-rnegex 7955 ax-cnre 7957 ax-pre-ltadd 7962 |
This theorem depends on definitions: df-bi 117 df-3an 982 df-tru 1367 df-fal 1370 df-nf 1472 df-sb 1774 df-eu 2041 df-mo 2042 df-clab 2176 df-cleq 2182 df-clel 2185 df-nfc 2321 df-ne 2361 df-nel 2456 df-ral 2473 df-rex 2474 df-reu 2475 df-rab 2477 df-v 2754 df-sbc 2978 df-dif 3146 df-un 3148 df-in 3150 df-ss 3157 df-pw 3595 df-sn 3616 df-pr 3617 df-op 3619 df-uni 3828 df-br 4022 df-opab 4083 df-id 4314 df-xp 4653 df-rel 4654 df-cnv 4655 df-co 4656 df-dm 4657 df-iota 5199 df-fun 5240 df-fv 5246 df-riota 5855 df-ov 5903 df-oprab 5904 df-mpo 5905 df-pnf 8029 df-mnf 8030 df-ltxr 8032 df-sub 8165 df-neg 8166 |
This theorem is referenced by: ltnegcon1 8455 ltnegcon2 8456 lt0neg1 8460 lt0neg2 8461 eqord2 8476 ltnegi 8485 ltnegd 8515 reapneg 8589 negiso 8947 xltnegi 9871 iooneg 10024 |
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