pnfneige0 - Mathbox for Thierry Arnoux

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Theorem pnfneige0 33229

Description: A neighborhood of +∞ contains an unbounded interval based at a real number. See pnfnei 22944. (Contributed by Thierry Arnoux, 31-Jul-2017.)

**Hypothesis**
Ref	Expression
pnfneige0.j	⊢ 𝐽 = (TopOpen‘(ℝ^*_𝑠 ↾_s (0[,]+∞)))

**Assertion**
Ref	Expression
pnfneige0	⊢ ((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) → ∃𝑥 ∈ ℝ (𝑥(,]+∞) ⊆ 𝐴)

Distinct variable group: 𝑥,𝐴 Allowed substitution hint: 𝐽(𝑥)

Proof of Theorem pnfneige0 Dummy variable 𝑦 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		0red 11221	. . . 4 ⊢ (((((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) ∧ 𝑦 ∈ ℝ) ∧ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞))) ∧ 𝑦 < 0) → 0 ∈ ℝ)
2		simpllr 772	. . . 4 ⊢ (((((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) ∧ 𝑦 ∈ ℝ) ∧ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞))) ∧ ¬ 𝑦 < 0) → 𝑦 ∈ ℝ)
3	1, 2	ifclda 4562	. . 3 ⊢ ((((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) ∧ 𝑦 ∈ ℝ) ∧ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞))) → if(𝑦 < 0, 0, 𝑦) ∈ ℝ)
4		ovif 7508	. . . . . 6 ⊢ (if(𝑦 < 0, 0, 𝑦)(,]+∞) = if(𝑦 < 0, (0(,]+∞), (𝑦(,]+∞))
5		rexr 11264	. . . . . . 7 ⊢ (𝑦 ∈ ℝ → 𝑦 ∈ ℝ^*)
6		0xr 11265	. . . . . . . 8 ⊢ 0 ∈ ℝ^*
7	6	a1i 11	. . . . . . 7 ⊢ (𝑦 ∈ ℝ → 0 ∈ ℝ^*)
8		pnfxr 11272	. . . . . . . 8 ⊢ +∞ ∈ ℝ^*
9	8	a1i 11	. . . . . . 7 ⊢ (𝑦 ∈ ℝ → +∞ ∈ ℝ^*)
10		iocinif 32259	. . . . . . 7 ⊢ ((𝑦 ∈ ℝ^* ∧ 0 ∈ ℝ^* ∧ +∞ ∈ ℝ^*) → ((𝑦(,]+∞) ∩ (0(,]+∞)) = if(𝑦 < 0, (0(,]+∞), (𝑦(,]+∞)))
11	5, 7, 9, 10	syl3anc 1369	. . . . . 6 ⊢ (𝑦 ∈ ℝ → ((𝑦(,]+∞) ∩ (0(,]+∞)) = if(𝑦 < 0, (0(,]+∞), (𝑦(,]+∞)))
12	4, 11	eqtr4id 2789	. . . . 5 ⊢ (𝑦 ∈ ℝ → (if(𝑦 < 0, 0, 𝑦)(,]+∞) = ((𝑦(,]+∞) ∩ (0(,]+∞)))
13	12	ad2antlr 723	. . . 4 ⊢ ((((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) ∧ 𝑦 ∈ ℝ) ∧ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞))) → (if(𝑦 < 0, 0, 𝑦)(,]+∞) = ((𝑦(,]+∞) ∩ (0(,]+∞)))
14		iocssicc 13418	. . . . . 6 ⊢ (0(,]+∞) ⊆ (0[,]+∞)
15		sslin 4233	. . . . . 6 ⊢ ((0(,]+∞) ⊆ (0[,]+∞) → ((𝑦(,]+∞) ∩ (0(,]+∞)) ⊆ ((𝑦(,]+∞) ∩ (0[,]+∞)))
16	14, 15	mp1i 13	. . . . 5 ⊢ ((((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) ∧ 𝑦 ∈ ℝ) ∧ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞))) → ((𝑦(,]+∞) ∩ (0(,]+∞)) ⊆ ((𝑦(,]+∞) ∩ (0[,]+∞)))
17		simpr 483	. . . . . 6 ⊢ ((((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) ∧ 𝑦 ∈ ℝ) ∧ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞))) → (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞)))
18		ssin 4229	. . . . . . . 8 ⊢ (((𝑦(,]+∞) ⊆ 𝐴 ∧ (𝑦(,]+∞) ⊆ (0(,]+∞)) ↔ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞)))
19	18	biimpri 227	. . . . . . 7 ⊢ ((𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞)) → ((𝑦(,]+∞) ⊆ 𝐴 ∧ (𝑦(,]+∞) ⊆ (0(,]+∞)))
20	19	simpld 493	. . . . . 6 ⊢ ((𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞)) → (𝑦(,]+∞) ⊆ 𝐴)
21		ssinss1 4236	. . . . . 6 ⊢ ((𝑦(,]+∞) ⊆ 𝐴 → ((𝑦(,]+∞) ∩ (0[,]+∞)) ⊆ 𝐴)
22	17, 20, 21	3syl 18	. . . . 5 ⊢ ((((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) ∧ 𝑦 ∈ ℝ) ∧ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞))) → ((𝑦(,]+∞) ∩ (0[,]+∞)) ⊆ 𝐴)
23	16, 22	sstrd 3991	. . . 4 ⊢ ((((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) ∧ 𝑦 ∈ ℝ) ∧ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞))) → ((𝑦(,]+∞) ∩ (0(,]+∞)) ⊆ 𝐴)
24	13, 23	eqsstrd 4019	. . 3 ⊢ ((((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) ∧ 𝑦 ∈ ℝ) ∧ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞))) → (if(𝑦 < 0, 0, 𝑦)(,]+∞) ⊆ 𝐴)
25		oveq1 7418	. . . . 5 ⊢ (𝑥 = if(𝑦 < 0, 0, 𝑦) → (𝑥(,]+∞) = (if(𝑦 < 0, 0, 𝑦)(,]+∞))
26	25	sseq1d 4012	. . . 4 ⊢ (𝑥 = if(𝑦 < 0, 0, 𝑦) → ((𝑥(,]+∞) ⊆ 𝐴 ↔ (if(𝑦 < 0, 0, 𝑦)(,]+∞) ⊆ 𝐴))
27	26	rspcev 3611	. . 3 ⊢ ((if(𝑦 < 0, 0, 𝑦) ∈ ℝ ∧ (if(𝑦 < 0, 0, 𝑦)(,]+∞) ⊆ 𝐴) → ∃𝑥 ∈ ℝ (𝑥(,]+∞) ⊆ 𝐴)
28	3, 24, 27	syl2anc 582	. 2 ⊢ ((((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) ∧ 𝑦 ∈ ℝ) ∧ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞))) → ∃𝑥 ∈ ℝ (𝑥(,]+∞) ⊆ 𝐴)
29		letopon 22929	. . . . . . . . . 10 ⊢ (ordTop‘ ≤ ) ∈ (TopOn‘ℝ^*)
30		iccssxr 13411	. . . . . . . . . 10 ⊢ (0[,]+∞) ⊆ ℝ^*
31		resttopon 22885	. . . . . . . . . 10 ⊢ (((ordTop‘ ≤ ) ∈ (TopOn‘ℝ^) ∧ (0[,]+∞) ⊆ ℝ^) → ((ordTop‘ ≤ ) ↾_t (0[,]+∞)) ∈ (TopOn‘(0[,]+∞)))
32	29, 30, 31	mp2an 688	. . . . . . . . 9 ⊢ ((ordTop‘ ≤ ) ↾_t (0[,]+∞)) ∈ (TopOn‘(0[,]+∞))
33	32	topontopi 22637	. . . . . . . 8 ⊢ ((ordTop‘ ≤ ) ↾_t (0[,]+∞)) ∈ Top
34	33	a1i 11	. . . . . . 7 ⊢ (𝐴 ∈ 𝐽 → ((ordTop‘ ≤ ) ↾_t (0[,]+∞)) ∈ Top)
35		ovex 7444	. . . . . . . 8 ⊢ (0(,]+∞) ∈ V
36	35	a1i 11	. . . . . . 7 ⊢ (𝐴 ∈ 𝐽 → (0(,]+∞) ∈ V)
37		pnfneige0.j	. . . . . . . . . 10 ⊢ 𝐽 = (TopOpen‘(ℝ^*_𝑠 ↾_s (0[,]+∞)))
38		xrge0topn 33221	. . . . . . . . . 10 ⊢ (TopOpen‘(ℝ^*_𝑠 ↾_s (0[,]+∞))) = ((ordTop‘ ≤ ) ↾_t (0[,]+∞))
39	37, 38	eqtri 2758	. . . . . . . . 9 ⊢ 𝐽 = ((ordTop‘ ≤ ) ↾_t (0[,]+∞))
40	39	eleq2i 2823	. . . . . . . 8 ⊢ (𝐴 ∈ 𝐽 ↔ 𝐴 ∈ ((ordTop‘ ≤ ) ↾_t (0[,]+∞)))
41	40	biimpi 215	. . . . . . 7 ⊢ (𝐴 ∈ 𝐽 → 𝐴 ∈ ((ordTop‘ ≤ ) ↾_t (0[,]+∞)))
42		elrestr 17378	. . . . . . 7 ⊢ ((((ordTop‘ ≤ ) ↾_t (0[,]+∞)) ∈ Top ∧ (0(,]+∞) ∈ V ∧ 𝐴 ∈ ((ordTop‘ ≤ ) ↾_t (0[,]+∞))) → (𝐴 ∩ (0(,]+∞)) ∈ (((ordTop‘ ≤ ) ↾_t (0[,]+∞)) ↾_t (0(,]+∞)))
43	34, 36, 41, 42	syl3anc 1369	. . . . . 6 ⊢ (𝐴 ∈ 𝐽 → (𝐴 ∩ (0(,]+∞)) ∈ (((ordTop‘ ≤ ) ↾_t (0[,]+∞)) ↾_t (0(,]+∞)))
44		letop 22930	. . . . . . 7 ⊢ (ordTop‘ ≤ ) ∈ Top
45		ovex 7444	. . . . . . 7 ⊢ (0[,]+∞) ∈ V
46		restabs 22889	. . . . . . 7 ⊢ (((ordTop‘ ≤ ) ∈ Top ∧ (0(,]+∞) ⊆ (0[,]+∞) ∧ (0[,]+∞) ∈ V) → (((ordTop‘ ≤ ) ↾_t (0[,]+∞)) ↾_t (0(,]+∞)) = ((ordTop‘ ≤ ) ↾_t (0(,]+∞)))
47	44, 14, 45, 46	mp3an 1459	. . . . . 6 ⊢ (((ordTop‘ ≤ ) ↾_t (0[,]+∞)) ↾_t (0(,]+∞)) = ((ordTop‘ ≤ ) ↾_t (0(,]+∞))
48	43, 47	eleqtrdi 2841	. . . . 5 ⊢ (𝐴 ∈ 𝐽 → (𝐴 ∩ (0(,]+∞)) ∈ ((ordTop‘ ≤ ) ↾_t (0(,]+∞)))
49	44	a1i 11	. . . . . 6 ⊢ (𝐴 ∈ 𝐽 → (ordTop‘ ≤ ) ∈ Top)
50		iocpnfordt 22939	. . . . . . 7 ⊢ (0(,]+∞) ∈ (ordTop‘ ≤ )
51	50	a1i 11	. . . . . 6 ⊢ (𝐴 ∈ 𝐽 → (0(,]+∞) ∈ (ordTop‘ ≤ ))
52		ssidd 4004	. . . . . 6 ⊢ (𝐴 ∈ 𝐽 → (0(,]+∞) ⊆ (0(,]+∞))
53		inss2 4228	. . . . . . 7 ⊢ (𝐴 ∩ (0(,]+∞)) ⊆ (0(,]+∞)
54	53	a1i 11	. . . . . 6 ⊢ (𝐴 ∈ 𝐽 → (𝐴 ∩ (0(,]+∞)) ⊆ (0(,]+∞))
55		restopnb 22899	. . . . . 6 ⊢ ((((ordTop‘ ≤ ) ∈ Top ∧ (0(,]+∞) ∈ V) ∧ ((0(,]+∞) ∈ (ordTop‘ ≤ ) ∧ (0(,]+∞) ⊆ (0(,]+∞) ∧ (𝐴 ∩ (0(,]+∞)) ⊆ (0(,]+∞))) → ((𝐴 ∩ (0(,]+∞)) ∈ (ordTop‘ ≤ ) ↔ (𝐴 ∩ (0(,]+∞)) ∈ ((ordTop‘ ≤ ) ↾_t (0(,]+∞))))
56	49, 36, 51, 52, 54, 55	syl23anc 1375	. . . . 5 ⊢ (𝐴 ∈ 𝐽 → ((𝐴 ∩ (0(,]+∞)) ∈ (ordTop‘ ≤ ) ↔ (𝐴 ∩ (0(,]+∞)) ∈ ((ordTop‘ ≤ ) ↾_t (0(,]+∞))))
57	48, 56	mpbird 256	. . . 4 ⊢ (𝐴 ∈ 𝐽 → (𝐴 ∩ (0(,]+∞)) ∈ (ordTop‘ ≤ ))
58	57	adantr 479	. . 3 ⊢ ((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) → (𝐴 ∩ (0(,]+∞)) ∈ (ordTop‘ ≤ ))
59		simpr 483	. . . 4 ⊢ ((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) → +∞ ∈ 𝐴)
60		0ltpnf 13106	. . . . . 6 ⊢ 0 < +∞
61		ubioc1 13381	. . . . . 6 ⊢ ((0 ∈ ℝ^* ∧ +∞ ∈ ℝ^* ∧ 0 < +∞) → +∞ ∈ (0(,]+∞))
62	6, 8, 60, 61	mp3an 1459	. . . . 5 ⊢ +∞ ∈ (0(,]+∞)
63	62	a1i 11	. . . 4 ⊢ ((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) → +∞ ∈ (0(,]+∞))
64	59, 63	elind 4193	. . 3 ⊢ ((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) → +∞ ∈ (𝐴 ∩ (0(,]+∞)))
65		pnfnei 22944	. . 3 ⊢ (((𝐴 ∩ (0(,]+∞)) ∈ (ordTop‘ ≤ ) ∧ +∞ ∈ (𝐴 ∩ (0(,]+∞))) → ∃𝑦 ∈ ℝ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞)))
66	58, 64, 65	syl2anc 582	. 2 ⊢ ((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) → ∃𝑦 ∈ ℝ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞)))
67	28, 66	r19.29a 3160	1 ⊢ ((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) → ∃𝑥 ∈ ℝ (𝑥(,]+∞) ⊆ 𝐴)

Colors of variables: wff setvar class

Syntax hints: ¬ wn 3 → wi 4 ↔ wb 205 ∧ wa 394 = wceq 1539 ∈ wcel 2104 ∃wrex 3068 Vcvv 3472 ∩ cin 3946 ⊆ wss 3947 ifcif 4527 class class class wbr 5147 ‘cfv 6542 (class class class)co 7411 ℝcr 11111 0cc0 11112 +∞cpnf 11249 ℝ^*cxr 11251 < clt 11252 ≤ cle 11253 (,]cioc 13329 [,]cicc 13331 ↾_s cress 17177 ↾_t crest 17370 TopOpenctopn 17371 ordTopcordt 17449 ℝ^*_𝑠cxrs 17450 Topctop 22615 TopOnctopon 22632

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 1911 ax-6 1969 ax-7 2009 ax-8 2106 ax-9 2114 ax-10 2135 ax-11 2152 ax-12 2169 ax-ext 2701 ax-rep 5284 ax-sep 5298 ax-nul 5305 ax-pow 5362 ax-pr 5426 ax-un 7727 ax-cnex 11168 ax-resscn 11169 ax-1cn 11170 ax-icn 11171 ax-addcl 11172 ax-addrcl 11173 ax-mulcl 11174 ax-mulrcl 11175 ax-mulcom 11176 ax-addass 11177 ax-mulass 11178 ax-distr 11179 ax-i2m1 11180 ax-1ne0 11181 ax-1rid 11182 ax-rnegex 11183 ax-rrecex 11184 ax-cnre 11185 ax-pre-lttri 11186 ax-pre-lttrn 11187 ax-pre-ltadd 11188 ax-pre-mulgt0 11189

This theorem depends on definitions: df-bi 206 df-an 395 df-or 844 df-3or 1086 df-3an 1087 df-tru 1542 df-fal 1552 df-ex 1780 df-nf 1784 df-sb 2066 df-mo 2532 df-eu 2561 df-clab 2708 df-cleq 2722 df-clel 2808 df-nfc 2883 df-ne 2939 df-nel 3045 df-ral 3060 df-rex 3069 df-reu 3375 df-rab 3431 df-v 3474 df-sbc 3777 df-csb 3893 df-dif 3950 df-un 3952 df-in 3954 df-ss 3964 df-pss 3966 df-nul 4322 df-if 4528 df-pw 4603 df-sn 4628 df-pr 4630 df-tp 4632 df-op 4634 df-uni 4908 df-int 4950 df-iun 4998 df-br 5148 df-opab 5210 df-mpt 5231 df-tr 5265 df-id 5573 df-eprel 5579 df-po 5587 df-so 5588 df-fr 5630 df-we 5632 df-xp 5681 df-rel 5682 df-cnv 5683 df-co 5684 df-dm 5685 df-rn 5686 df-res 5687 df-ima 5688 df-pred 6299 df-ord 6366 df-on 6367 df-lim 6368 df-suc 6369 df-iota 6494 df-fun 6544 df-fn 6545 df-f 6546 df-f1 6547 df-fo 6548 df-f1o 6549 df-fv 6550 df-riota 7367 df-ov 7414 df-oprab 7415 df-mpo 7416 df-om 7858 df-1st 7977 df-2nd 7978 df-frecs 8268 df-wrecs 8299 df-recs 8373 df-rdg 8412 df-1o 8468 df-er 8705 df-en 8942 df-dom 8943 df-sdom 8944 df-fin 8945 df-fi 9408 df-pnf 11254 df-mnf 11255 df-xr 11256 df-ltxr 11257 df-le 11258 df-sub 11450 df-neg 11451 df-nn 12217 df-2 12279 df-3 12280 df-4 12281 df-5 12282 df-6 12283 df-7 12284 df-8 12285 df-9 12286 df-n0 12477 df-z 12563 df-dec 12682 df-uz 12827 df-ioo 13332 df-ioc 13333 df-ico 13334 df-icc 13335 df-fz 13489 df-struct 17084 df-sets 17101 df-slot 17119 df-ndx 17131 df-base 17149 df-ress 17178 df-plusg 17214 df-mulr 17215 df-tset 17220 df-ple 17221 df-ds 17223 df-rest 17372 df-topn 17373 df-topgen 17393 df-ordt 17451 df-xrs 17452 df-ps 18523 df-tsr 18524 df-top 22616 df-topon 22633 df-bases 22669

This theorem is referenced by: lmxrge0 33230

W3C validator