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Mirrors > Home > ILE Home > Th. List > xaddnemnf | GIF version |
Description: Closure of extended real addition in the subset ℝ* / {-∞}. (Contributed by Mario Carneiro, 20-Aug-2015.) |
Ref | Expression |
---|---|
xaddnemnf | ⊢ (((𝐴 ∈ ℝ* ∧ 𝐴 ≠ -∞) ∧ (𝐵 ∈ ℝ* ∧ 𝐵 ≠ -∞)) → (𝐴 +𝑒 𝐵) ≠ -∞) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | xrnemnf 9779 | . 2 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐴 ≠ -∞) ↔ (𝐴 ∈ ℝ ∨ 𝐴 = +∞)) | |
2 | xrnemnf 9779 | . . . 4 ⊢ ((𝐵 ∈ ℝ* ∧ 𝐵 ≠ -∞) ↔ (𝐵 ∈ ℝ ∨ 𝐵 = +∞)) | |
3 | rexadd 9854 | . . . . . . 7 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 +𝑒 𝐵) = (𝐴 + 𝐵)) | |
4 | readdcl 7939 | . . . . . . 7 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 + 𝐵) ∈ ℝ) | |
5 | 3, 4 | eqeltrd 2254 | . . . . . 6 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 +𝑒 𝐵) ∈ ℝ) |
6 | 5 | renemnfd 8011 | . . . . 5 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 +𝑒 𝐵) ≠ -∞) |
7 | oveq2 5885 | . . . . . . 7 ⊢ (𝐵 = +∞ → (𝐴 +𝑒 𝐵) = (𝐴 +𝑒 +∞)) | |
8 | rexr 8005 | . . . . . . . 8 ⊢ (𝐴 ∈ ℝ → 𝐴 ∈ ℝ*) | |
9 | renemnf 8008 | . . . . . . . 8 ⊢ (𝐴 ∈ ℝ → 𝐴 ≠ -∞) | |
10 | xaddpnf1 9848 | . . . . . . . 8 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐴 ≠ -∞) → (𝐴 +𝑒 +∞) = +∞) | |
11 | 8, 9, 10 | syl2anc 411 | . . . . . . 7 ⊢ (𝐴 ∈ ℝ → (𝐴 +𝑒 +∞) = +∞) |
12 | 7, 11 | sylan9eqr 2232 | . . . . . 6 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 = +∞) → (𝐴 +𝑒 𝐵) = +∞) |
13 | pnfnemnf 8014 | . . . . . . 7 ⊢ +∞ ≠ -∞ | |
14 | 13 | a1i 9 | . . . . . 6 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 = +∞) → +∞ ≠ -∞) |
15 | 12, 14 | eqnetrd 2371 | . . . . 5 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 = +∞) → (𝐴 +𝑒 𝐵) ≠ -∞) |
16 | 6, 15 | jaodan 797 | . . . 4 ⊢ ((𝐴 ∈ ℝ ∧ (𝐵 ∈ ℝ ∨ 𝐵 = +∞)) → (𝐴 +𝑒 𝐵) ≠ -∞) |
17 | 2, 16 | sylan2b 287 | . . 3 ⊢ ((𝐴 ∈ ℝ ∧ (𝐵 ∈ ℝ* ∧ 𝐵 ≠ -∞)) → (𝐴 +𝑒 𝐵) ≠ -∞) |
18 | oveq1 5884 | . . . . 5 ⊢ (𝐴 = +∞ → (𝐴 +𝑒 𝐵) = (+∞ +𝑒 𝐵)) | |
19 | xaddpnf2 9849 | . . . . 5 ⊢ ((𝐵 ∈ ℝ* ∧ 𝐵 ≠ -∞) → (+∞ +𝑒 𝐵) = +∞) | |
20 | 18, 19 | sylan9eq 2230 | . . . 4 ⊢ ((𝐴 = +∞ ∧ (𝐵 ∈ ℝ* ∧ 𝐵 ≠ -∞)) → (𝐴 +𝑒 𝐵) = +∞) |
21 | 13 | a1i 9 | . . . 4 ⊢ ((𝐴 = +∞ ∧ (𝐵 ∈ ℝ* ∧ 𝐵 ≠ -∞)) → +∞ ≠ -∞) |
22 | 20, 21 | eqnetrd 2371 | . . 3 ⊢ ((𝐴 = +∞ ∧ (𝐵 ∈ ℝ* ∧ 𝐵 ≠ -∞)) → (𝐴 +𝑒 𝐵) ≠ -∞) |
23 | 17, 22 | jaoian 795 | . 2 ⊢ (((𝐴 ∈ ℝ ∨ 𝐴 = +∞) ∧ (𝐵 ∈ ℝ* ∧ 𝐵 ≠ -∞)) → (𝐴 +𝑒 𝐵) ≠ -∞) |
24 | 1, 23 | sylanb 284 | 1 ⊢ (((𝐴 ∈ ℝ* ∧ 𝐴 ≠ -∞) ∧ (𝐵 ∈ ℝ* ∧ 𝐵 ≠ -∞)) → (𝐴 +𝑒 𝐵) ≠ -∞) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 104 ∨ wo 708 = wceq 1353 ∈ wcel 2148 ≠ wne 2347 (class class class)co 5877 ℝcr 7812 + caddc 7816 +∞cpnf 7991 -∞cmnf 7992 ℝ*cxr 7993 +𝑒 cxad 9772 |
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 614 ax-in2 615 ax-io 709 ax-5 1447 ax-7 1448 ax-gen 1449 ax-ie1 1493 ax-ie2 1494 ax-8 1504 ax-10 1505 ax-11 1506 ax-i12 1507 ax-bndl 1509 ax-4 1510 ax-17 1526 ax-i9 1530 ax-ial 1534 ax-i5r 1535 ax-13 2150 ax-14 2151 ax-ext 2159 ax-sep 4123 ax-pow 4176 ax-pr 4211 ax-un 4435 ax-setind 4538 ax-cnex 7904 ax-resscn 7905 ax-1re 7907 ax-addrcl 7910 ax-rnegex 7922 |
This theorem depends on definitions: df-bi 117 df-dc 835 df-3or 979 df-3an 980 df-tru 1356 df-fal 1359 df-nf 1461 df-sb 1763 df-eu 2029 df-mo 2030 df-clab 2164 df-cleq 2170 df-clel 2173 df-nfc 2308 df-ne 2348 df-nel 2443 df-ral 2460 df-rex 2461 df-rab 2464 df-v 2741 df-sbc 2965 df-dif 3133 df-un 3135 df-in 3137 df-ss 3144 df-if 3537 df-pw 3579 df-sn 3600 df-pr 3601 df-op 3603 df-uni 3812 df-br 4006 df-opab 4067 df-id 4295 df-xp 4634 df-rel 4635 df-cnv 4636 df-co 4637 df-dm 4638 df-iota 5180 df-fun 5220 df-fv 5226 df-ov 5880 df-oprab 5881 df-mpo 5882 df-pnf 7996 df-mnf 7997 df-xr 7998 df-xadd 9775 |
This theorem is referenced by: xaddass 9871 xlt2add 9882 xadd4d 9887 xleaddadd 9889 |
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