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| Mirrors > Home > ILE Home > Th. List > recexgt0 | GIF version | ||
| Description: Existence of reciprocal of positive real number. (Contributed by Jim Kingdon, 6-Feb-2020.) | 
| Ref | Expression | 
|---|---|
| recexgt0 | ⊢ ((𝐴 ∈ ℝ ∧ 0 < 𝐴) → ∃𝑥 ∈ ℝ (0 < 𝑥 ∧ (𝐴 · 𝑥) = 1)) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | ax-precex 7989 | . 2 ⊢ ((𝐴 ∈ ℝ ∧ 0 <ℝ 𝐴) → ∃𝑥 ∈ ℝ (0 <ℝ 𝑥 ∧ (𝐴 · 𝑥) = 1)) | |
| 2 | 0re 8026 | . . . 4 ⊢ 0 ∈ ℝ | |
| 3 | ltxrlt 8092 | . . . 4 ⊢ ((0 ∈ ℝ ∧ 𝐴 ∈ ℝ) → (0 < 𝐴 ↔ 0 <ℝ 𝐴)) | |
| 4 | 2, 3 | mpan 424 | . . 3 ⊢ (𝐴 ∈ ℝ → (0 < 𝐴 ↔ 0 <ℝ 𝐴)) | 
| 5 | 4 | pm5.32i 454 | . 2 ⊢ ((𝐴 ∈ ℝ ∧ 0 < 𝐴) ↔ (𝐴 ∈ ℝ ∧ 0 <ℝ 𝐴)) | 
| 6 | ltxrlt 8092 | . . . . 5 ⊢ ((0 ∈ ℝ ∧ 𝑥 ∈ ℝ) → (0 < 𝑥 ↔ 0 <ℝ 𝑥)) | |
| 7 | 2, 6 | mpan 424 | . . . 4 ⊢ (𝑥 ∈ ℝ → (0 < 𝑥 ↔ 0 <ℝ 𝑥)) | 
| 8 | 7 | anbi1d 465 | . . 3 ⊢ (𝑥 ∈ ℝ → ((0 < 𝑥 ∧ (𝐴 · 𝑥) = 1) ↔ (0 <ℝ 𝑥 ∧ (𝐴 · 𝑥) = 1))) | 
| 9 | 8 | rexbiia 2512 | . 2 ⊢ (∃𝑥 ∈ ℝ (0 < 𝑥 ∧ (𝐴 · 𝑥) = 1) ↔ ∃𝑥 ∈ ℝ (0 <ℝ 𝑥 ∧ (𝐴 · 𝑥) = 1)) | 
| 10 | 1, 5, 9 | 3imtr4i 201 | 1 ⊢ ((𝐴 ∈ ℝ ∧ 0 < 𝐴) → ∃𝑥 ∈ ℝ (0 < 𝑥 ∧ (𝐴 · 𝑥) = 1)) | 
| Colors of variables: wff set class | 
| Syntax hints: → wi 4 ∧ wa 104 ↔ wb 105 = wceq 1364 ∈ wcel 2167 ∃wrex 2476 class class class wbr 4033 (class class class)co 5922 ℝcr 7878 0cc0 7879 1c1 7880 <ℝ cltrr 7883 · cmul 7884 < clt 8061 | 
| 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 1461 ax-7 1462 ax-gen 1463 ax-ie1 1507 ax-ie2 1508 ax-8 1518 ax-10 1519 ax-11 1520 ax-i12 1521 ax-bndl 1523 ax-4 1524 ax-17 1540 ax-i9 1544 ax-ial 1548 ax-i5r 1549 ax-13 2169 ax-14 2170 ax-ext 2178 ax-sep 4151 ax-pow 4207 ax-pr 4242 ax-un 4468 ax-setind 4573 ax-cnex 7970 ax-resscn 7971 ax-1re 7973 ax-addrcl 7976 ax-rnegex 7988 ax-precex 7989 | 
| This theorem depends on definitions: df-bi 117 df-3an 982 df-tru 1367 df-fal 1370 df-nf 1475 df-sb 1777 df-eu 2048 df-mo 2049 df-clab 2183 df-cleq 2189 df-clel 2192 df-nfc 2328 df-ne 2368 df-nel 2463 df-ral 2480 df-rex 2481 df-rab 2484 df-v 2765 df-dif 3159 df-un 3161 df-in 3163 df-ss 3170 df-pw 3607 df-sn 3628 df-pr 3629 df-op 3631 df-uni 3840 df-br 4034 df-opab 4095 df-xp 4669 df-pnf 8063 df-mnf 8064 df-ltxr 8066 | 
| This theorem is referenced by: ltmul1 8619 | 
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