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Mirrors > Home > MPE Home > Th. List > xnegex | Structured version Visualization version GIF version |
Description: A negative extended real exists as a set. (Contributed by Mario Carneiro, 20-Aug-2015.) |
Ref | Expression |
---|---|
xnegex | ⊢ -𝑒𝐴 ∈ V |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-xneg 12508 | . 2 ⊢ -𝑒𝐴 = if(𝐴 = +∞, -∞, if(𝐴 = -∞, +∞, -𝐴)) | |
2 | mnfxr 10698 | . . . 4 ⊢ -∞ ∈ ℝ* | |
3 | 2 | elexi 3513 | . . 3 ⊢ -∞ ∈ V |
4 | pnfex 10694 | . . . 4 ⊢ +∞ ∈ V | |
5 | negex 10884 | . . . 4 ⊢ -𝐴 ∈ V | |
6 | 4, 5 | ifex 4515 | . . 3 ⊢ if(𝐴 = -∞, +∞, -𝐴) ∈ V |
7 | 3, 6 | ifex 4515 | . 2 ⊢ if(𝐴 = +∞, -∞, if(𝐴 = -∞, +∞, -𝐴)) ∈ V |
8 | 1, 7 | eqeltri 2909 | 1 ⊢ -𝑒𝐴 ∈ V |
Colors of variables: wff setvar class |
Syntax hints: = wceq 1537 ∈ wcel 2114 Vcvv 3494 ifcif 4467 +∞cpnf 10672 -∞cmnf 10673 ℝ*cxr 10674 -cneg 10871 -𝑒cxne 12505 |
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-un 7461 ax-cnex 10593 |
This theorem depends on definitions: df-bi 209 df-an 399 df-or 844 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-ral 3143 df-rex 3144 df-v 3496 df-sbc 3773 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-uni 4839 df-iota 6314 df-fv 6363 df-ov 7159 df-pnf 10677 df-mnf 10678 df-xr 10679 df-neg 10873 df-xneg 12508 |
This theorem is referenced by: xrhmeo 23550 supminfxrrnmpt 41767 monoord2xrv 41780 liminfvalxr 42084 liminfpnfuz 42117 xlimpnfxnegmnf2 42159 |
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