Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
||
Mirrors > Home > MPE Home > Th. List > prodge0rd | Structured version Visualization version GIF version |
Description: Infer that a multiplicand is nonnegative from a positive multiplier and nonnegative product. (Contributed by NM, 2-Jul-2005.) (Revised by Mario Carneiro, 27-May-2016.) (Revised by AV, 9-Jul-2022.) |
Ref | Expression |
---|---|
prodge0rd.1 | ⊢ (𝜑 → 𝐴 ∈ ℝ+) |
prodge0rd.2 | ⊢ (𝜑 → 𝐵 ∈ ℝ) |
prodge0rd.3 | ⊢ (𝜑 → 0 ≤ (𝐴 · 𝐵)) |
Ref | Expression |
---|---|
prodge0rd | ⊢ (𝜑 → 0 ≤ 𝐵) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 0red 10644 | . 2 ⊢ (𝜑 → 0 ∈ ℝ) | |
2 | prodge0rd.2 | . 2 ⊢ (𝜑 → 𝐵 ∈ ℝ) | |
3 | prodge0rd.1 | . . . . . 6 ⊢ (𝜑 → 𝐴 ∈ ℝ+) | |
4 | 3 | rpred 12432 | . . . . 5 ⊢ (𝜑 → 𝐴 ∈ ℝ) |
5 | 4, 2 | remulcld 10671 | . . . 4 ⊢ (𝜑 → (𝐴 · 𝐵) ∈ ℝ) |
6 | prodge0rd.3 | . . . 4 ⊢ (𝜑 → 0 ≤ (𝐴 · 𝐵)) | |
7 | 1, 5, 6 | lensymd 10791 | . . 3 ⊢ (𝜑 → ¬ (𝐴 · 𝐵) < 0) |
8 | 4 | adantr 483 | . . . . . . 7 ⊢ ((𝜑 ∧ 0 < -𝐵) → 𝐴 ∈ ℝ) |
9 | 2 | renegcld 11067 | . . . . . . . 8 ⊢ (𝜑 → -𝐵 ∈ ℝ) |
10 | 9 | adantr 483 | . . . . . . 7 ⊢ ((𝜑 ∧ 0 < -𝐵) → -𝐵 ∈ ℝ) |
11 | 3 | rpgt0d 12435 | . . . . . . . 8 ⊢ (𝜑 → 0 < 𝐴) |
12 | 11 | adantr 483 | . . . . . . 7 ⊢ ((𝜑 ∧ 0 < -𝐵) → 0 < 𝐴) |
13 | simpr 487 | . . . . . . 7 ⊢ ((𝜑 ∧ 0 < -𝐵) → 0 < -𝐵) | |
14 | 8, 10, 12, 13 | mulgt0d 10795 | . . . . . 6 ⊢ ((𝜑 ∧ 0 < -𝐵) → 0 < (𝐴 · -𝐵)) |
15 | 4 | recnd 10669 | . . . . . . . 8 ⊢ (𝜑 → 𝐴 ∈ ℂ) |
16 | 15 | adantr 483 | . . . . . . 7 ⊢ ((𝜑 ∧ 0 < -𝐵) → 𝐴 ∈ ℂ) |
17 | 2 | recnd 10669 | . . . . . . . 8 ⊢ (𝜑 → 𝐵 ∈ ℂ) |
18 | 17 | adantr 483 | . . . . . . 7 ⊢ ((𝜑 ∧ 0 < -𝐵) → 𝐵 ∈ ℂ) |
19 | 16, 18 | mulneg2d 11094 | . . . . . 6 ⊢ ((𝜑 ∧ 0 < -𝐵) → (𝐴 · -𝐵) = -(𝐴 · 𝐵)) |
20 | 14, 19 | breqtrd 5092 | . . . . 5 ⊢ ((𝜑 ∧ 0 < -𝐵) → 0 < -(𝐴 · 𝐵)) |
21 | 20 | ex 415 | . . . 4 ⊢ (𝜑 → (0 < -𝐵 → 0 < -(𝐴 · 𝐵))) |
22 | 2 | lt0neg1d 11209 | . . . 4 ⊢ (𝜑 → (𝐵 < 0 ↔ 0 < -𝐵)) |
23 | 5 | lt0neg1d 11209 | . . . 4 ⊢ (𝜑 → ((𝐴 · 𝐵) < 0 ↔ 0 < -(𝐴 · 𝐵))) |
24 | 21, 22, 23 | 3imtr4d 296 | . . 3 ⊢ (𝜑 → (𝐵 < 0 → (𝐴 · 𝐵) < 0)) |
25 | 7, 24 | mtod 200 | . 2 ⊢ (𝜑 → ¬ 𝐵 < 0) |
26 | 1, 2, 25 | nltled 10790 | 1 ⊢ (𝜑 → 0 ≤ 𝐵) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 398 ∈ wcel 2114 class class class wbr 5066 (class class class)co 7156 ℂcc 10535 ℝcr 10536 0cc0 10537 · cmul 10542 < clt 10675 ≤ cle 10676 -cneg 10871 ℝ+crp 12390 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1796 ax-4 1810 ax-5 1911 ax-6 1970 ax-7 2015 ax-8 2116 ax-9 2124 ax-10 2145 ax-11 2161 ax-12 2177 ax-ext 2793 ax-sep 5203 ax-nul 5210 ax-pow 5266 ax-pr 5330 ax-un 7461 ax-resscn 10594 ax-1cn 10595 ax-icn 10596 ax-addcl 10597 ax-addrcl 10598 ax-mulcl 10599 ax-mulrcl 10600 ax-mulcom 10601 ax-addass 10602 ax-mulass 10603 ax-distr 10604 ax-i2m1 10605 ax-1ne0 10606 ax-1rid 10607 ax-rnegex 10608 ax-rrecex 10609 ax-cnre 10610 ax-pre-lttri 10611 ax-pre-lttrn 10612 ax-pre-ltadd 10613 ax-pre-mulgt0 10614 |
This theorem depends on definitions: df-bi 209 df-an 399 df-or 844 df-3or 1084 df-3an 1085 df-tru 1540 df-ex 1781 df-nf 1785 df-sb 2070 df-mo 2622 df-eu 2654 df-clab 2800 df-cleq 2814 df-clel 2893 df-nfc 2963 df-ne 3017 df-nel 3124 df-ral 3143 df-rex 3144 df-reu 3145 df-rab 3147 df-v 3496 df-sbc 3773 df-csb 3884 df-dif 3939 df-un 3941 df-in 3943 df-ss 3952 df-nul 4292 df-if 4468 df-pw 4541 df-sn 4568 df-pr 4570 df-op 4574 df-uni 4839 df-br 5067 df-opab 5129 df-mpt 5147 df-id 5460 df-po 5474 df-so 5475 df-xp 5561 df-rel 5562 df-cnv 5563 df-co 5564 df-dm 5565 df-rn 5566 df-res 5567 df-ima 5568 df-iota 6314 df-fun 6357 df-fn 6358 df-f 6359 df-f1 6360 df-fo 6361 df-f1o 6362 df-fv 6363 df-riota 7114 df-ov 7159 df-oprab 7160 df-mpo 7161 df-er 8289 df-en 8510 df-dom 8511 df-sdom 8512 df-pnf 10677 df-mnf 10678 df-xr 10679 df-ltxr 10680 df-le 10681 df-sub 10872 df-neg 10873 df-rp 12391 |
This theorem is referenced by: prodge0ld 12498 oexpneg 15694 evennn02n 15699 nvge0 28450 oexpnegALTV 43891 |
Copyright terms: Public domain | W3C validator |