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| Mirrors > Home > MPE Home > Th. List > xaddmnf2 | Structured version Visualization version GIF version | ||
| Description: Addition of negative infinity on the left. (Contributed by Mario Carneiro, 20-Aug-2015.) |
| Ref | Expression |
|---|---|
| xaddmnf2 | ⊢ ((𝐴 ∈ ℝ* ∧ 𝐴 ≠ +∞) → (-∞ +𝑒 𝐴) = -∞) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | mnfxr 11318 | . . 3 ⊢ -∞ ∈ ℝ* | |
| 2 | xaddval 13265 | . . 3 ⊢ ((-∞ ∈ ℝ* ∧ 𝐴 ∈ ℝ*) → (-∞ +𝑒 𝐴) = if(-∞ = +∞, if(𝐴 = -∞, 0, +∞), if(-∞ = -∞, if(𝐴 = +∞, 0, -∞), if(𝐴 = +∞, +∞, if(𝐴 = -∞, -∞, (-∞ + 𝐴)))))) | |
| 3 | 1, 2 | mpan 690 | . 2 ⊢ (𝐴 ∈ ℝ* → (-∞ +𝑒 𝐴) = if(-∞ = +∞, if(𝐴 = -∞, 0, +∞), if(-∞ = -∞, if(𝐴 = +∞, 0, -∞), if(𝐴 = +∞, +∞, if(𝐴 = -∞, -∞, (-∞ + 𝐴)))))) |
| 4 | mnfnepnf 11317 | . . . . 5 ⊢ -∞ ≠ +∞ | |
| 5 | ifnefalse 4537 | . . . . 5 ⊢ (-∞ ≠ +∞ → if(-∞ = +∞, if(𝐴 = -∞, 0, +∞), if(-∞ = -∞, if(𝐴 = +∞, 0, -∞), if(𝐴 = +∞, +∞, if(𝐴 = -∞, -∞, (-∞ + 𝐴))))) = if(-∞ = -∞, if(𝐴 = +∞, 0, -∞), if(𝐴 = +∞, +∞, if(𝐴 = -∞, -∞, (-∞ + 𝐴))))) | |
| 6 | 4, 5 | ax-mp 5 | . . . 4 ⊢ if(-∞ = +∞, if(𝐴 = -∞, 0, +∞), if(-∞ = -∞, if(𝐴 = +∞, 0, -∞), if(𝐴 = +∞, +∞, if(𝐴 = -∞, -∞, (-∞ + 𝐴))))) = if(-∞ = -∞, if(𝐴 = +∞, 0, -∞), if(𝐴 = +∞, +∞, if(𝐴 = -∞, -∞, (-∞ + 𝐴)))) |
| 7 | eqid 2737 | . . . . 5 ⊢ -∞ = -∞ | |
| 8 | 7 | iftruei 4532 | . . . 4 ⊢ if(-∞ = -∞, if(𝐴 = +∞, 0, -∞), if(𝐴 = +∞, +∞, if(𝐴 = -∞, -∞, (-∞ + 𝐴)))) = if(𝐴 = +∞, 0, -∞) |
| 9 | 6, 8 | eqtri 2765 | . . 3 ⊢ if(-∞ = +∞, if(𝐴 = -∞, 0, +∞), if(-∞ = -∞, if(𝐴 = +∞, 0, -∞), if(𝐴 = +∞, +∞, if(𝐴 = -∞, -∞, (-∞ + 𝐴))))) = if(𝐴 = +∞, 0, -∞) |
| 10 | ifnefalse 4537 | . . 3 ⊢ (𝐴 ≠ +∞ → if(𝐴 = +∞, 0, -∞) = -∞) | |
| 11 | 9, 10 | eqtrid 2789 | . 2 ⊢ (𝐴 ≠ +∞ → if(-∞ = +∞, if(𝐴 = -∞, 0, +∞), if(-∞ = -∞, if(𝐴 = +∞, 0, -∞), if(𝐴 = +∞, +∞, if(𝐴 = -∞, -∞, (-∞ + 𝐴))))) = -∞) |
| 12 | 3, 11 | sylan9eq 2797 | 1 ⊢ ((𝐴 ∈ ℝ* ∧ 𝐴 ≠ +∞) → (-∞ +𝑒 𝐴) = -∞) |
| Colors of variables: wff setvar class |
| Syntax hints: → wi 4 ∧ wa 395 = wceq 1540 ∈ wcel 2108 ≠ wne 2940 ifcif 4525 (class class class)co 7431 0cc0 11155 + caddc 11158 +∞cpnf 11292 -∞cmnf 11293 ℝ*cxr 11294 +𝑒 cxad 13152 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1795 ax-4 1809 ax-5 1910 ax-6 1967 ax-7 2007 ax-8 2110 ax-9 2118 ax-10 2141 ax-11 2157 ax-12 2177 ax-ext 2708 ax-sep 5296 ax-nul 5306 ax-pow 5365 ax-pr 5432 ax-un 7755 ax-cnex 11211 ax-1cn 11213 ax-icn 11214 ax-addcl 11215 ax-mulcl 11217 ax-i2m1 11223 |
| This theorem depends on definitions: df-bi 207 df-an 396 df-or 849 df-3an 1089 df-tru 1543 df-fal 1553 df-ex 1780 df-nf 1784 df-sb 2065 df-mo 2540 df-eu 2569 df-clab 2715 df-cleq 2729 df-clel 2816 df-nfc 2892 df-ne 2941 df-ral 3062 df-rex 3071 df-rab 3437 df-v 3482 df-sbc 3789 df-dif 3954 df-un 3956 df-in 3958 df-ss 3968 df-nul 4334 df-if 4526 df-pw 4602 df-sn 4627 df-pr 4629 df-op 4633 df-uni 4908 df-br 5144 df-opab 5206 df-id 5578 df-xp 5691 df-rel 5692 df-cnv 5693 df-co 5694 df-dm 5695 df-iota 6514 df-fun 6563 df-fv 6569 df-ov 7434 df-oprab 7435 df-mpo 7436 df-pnf 11297 df-mnf 11298 df-xr 11299 df-xadd 13155 |
| This theorem is referenced by: xaddnepnf 13279 xaddcom 13282 xaddrid 13283 xnegdi 13290 xpncan 13293 xleadd1a 13295 xlt2add 13302 xadddilem 13336 xadddi2 13339 xrsnsgrp 21420 xaddeq0 32757 supxrgelem 45348 supxrge 45349 xrlexaddrp 45363 infleinflem2 45382 |
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