pnfneige0 - Mathbox for Thierry Arnoux

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Theorem pnfneige0 33226

Description: A neighborhood of +∞ contains an unbounded interval based at a real number. See pnfnei 22945. (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 11222	. . . 4 ⊢ (((((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) ∧ 𝑦 ∈ ℝ) ∧ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞))) ∧ 𝑦 < 0) → 0 ∈ ℝ)
2		simpllr 773	. . . 4 ⊢ (((((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) ∧ 𝑦 ∈ ℝ) ∧ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞))) ∧ ¬ 𝑦 < 0) → 𝑦 ∈ ℝ)
3	1, 2	ifclda 4564	. . 3 ⊢ ((((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) ∧ 𝑦 ∈ ℝ) ∧ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞))) → if(𝑦 < 0, 0, 𝑦) ∈ ℝ)
4		ovif 7509	. . . . . 6 ⊢ (if(𝑦 < 0, 0, 𝑦)(,]+∞) = if(𝑦 < 0, (0(,]+∞), (𝑦(,]+∞))
5		rexr 11265	. . . . . . 7 ⊢ (𝑦 ∈ ℝ → 𝑦 ∈ ℝ^*)
6		0xr 11266	. . . . . . . 8 ⊢ 0 ∈ ℝ^*
7	6	a1i 11	. . . . . . 7 ⊢ (𝑦 ∈ ℝ → 0 ∈ ℝ^*)
8		pnfxr 11273	. . . . . . . 8 ⊢ +∞ ∈ ℝ^*
9	8	a1i 11	. . . . . . 7 ⊢ (𝑦 ∈ ℝ → +∞ ∈ ℝ^*)
10		iocinif 32256	. . . . . . 7 ⊢ ((𝑦 ∈ ℝ^* ∧ 0 ∈ ℝ^* ∧ +∞ ∈ ℝ^*) → ((𝑦(,]+∞) ∩ (0(,]+∞)) = if(𝑦 < 0, (0(,]+∞), (𝑦(,]+∞)))
11	5, 7, 9, 10	syl3anc 1370	. . . . . 6 ⊢ (𝑦 ∈ ℝ → ((𝑦(,]+∞) ∩ (0(,]+∞)) = if(𝑦 < 0, (0(,]+∞), (𝑦(,]+∞)))
12	4, 11	eqtr4id 2790	. . . . 5 ⊢ (𝑦 ∈ ℝ → (if(𝑦 < 0, 0, 𝑦)(,]+∞) = ((𝑦(,]+∞) ∩ (0(,]+∞)))
13	12	ad2antlr 724	. . . 4 ⊢ ((((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) ∧ 𝑦 ∈ ℝ) ∧ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞))) → (if(𝑦 < 0, 0, 𝑦)(,]+∞) = ((𝑦(,]+∞) ∩ (0(,]+∞)))
14		iocssicc 13419	. . . . . 6 ⊢ (0(,]+∞) ⊆ (0[,]+∞)
15		sslin 4235	. . . . . 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 484	. . . . . 6 ⊢ ((((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) ∧ 𝑦 ∈ ℝ) ∧ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞))) → (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞)))
18		ssin 4231	. . . . . . . 8 ⊢ (((𝑦(,]+∞) ⊆ 𝐴 ∧ (𝑦(,]+∞) ⊆ (0(,]+∞)) ↔ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞)))
19	18	biimpri 227	. . . . . . 7 ⊢ ((𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞)) → ((𝑦(,]+∞) ⊆ 𝐴 ∧ (𝑦(,]+∞) ⊆ (0(,]+∞)))
20	19	simpld 494	. . . . . 6 ⊢ ((𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞)) → (𝑦(,]+∞) ⊆ 𝐴)
21		ssinss1 4238	. . . . . 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 3993	. . . 4 ⊢ ((((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) ∧ 𝑦 ∈ ℝ) ∧ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞))) → ((𝑦(,]+∞) ∩ (0(,]+∞)) ⊆ 𝐴)
24	13, 23	eqsstrd 4021	. . 3 ⊢ ((((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) ∧ 𝑦 ∈ ℝ) ∧ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞))) → (if(𝑦 < 0, 0, 𝑦)(,]+∞) ⊆ 𝐴)
25		oveq1 7419	. . . . 5 ⊢ (𝑥 = if(𝑦 < 0, 0, 𝑦) → (𝑥(,]+∞) = (if(𝑦 < 0, 0, 𝑦)(,]+∞))
26	25	sseq1d 4014	. . . 4 ⊢ (𝑥 = if(𝑦 < 0, 0, 𝑦) → ((𝑥(,]+∞) ⊆ 𝐴 ↔ (if(𝑦 < 0, 0, 𝑦)(,]+∞) ⊆ 𝐴))
27	26	rspcev 3613	. . 3 ⊢ ((if(𝑦 < 0, 0, 𝑦) ∈ ℝ ∧ (if(𝑦 < 0, 0, 𝑦)(,]+∞) ⊆ 𝐴) → ∃𝑥 ∈ ℝ (𝑥(,]+∞) ⊆ 𝐴)
28	3, 24, 27	syl2anc 583	. 2 ⊢ ((((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) ∧ 𝑦 ∈ ℝ) ∧ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞))) → ∃𝑥 ∈ ℝ (𝑥(,]+∞) ⊆ 𝐴)
29		letopon 22930	. . . . . . . . . 10 ⊢ (ordTop‘ ≤ ) ∈ (TopOn‘ℝ^*)
30		iccssxr 13412	. . . . . . . . . 10 ⊢ (0[,]+∞) ⊆ ℝ^*
31		resttopon 22886	. . . . . . . . . 10 ⊢ (((ordTop‘ ≤ ) ∈ (TopOn‘ℝ^) ∧ (0[,]+∞) ⊆ ℝ^) → ((ordTop‘ ≤ ) ↾_t (0[,]+∞)) ∈ (TopOn‘(0[,]+∞)))
32	29, 30, 31	mp2an 689	. . . . . . . . 9 ⊢ ((ordTop‘ ≤ ) ↾_t (0[,]+∞)) ∈ (TopOn‘(0[,]+∞))
33	32	topontopi 22638	. . . . . . . 8 ⊢ ((ordTop‘ ≤ ) ↾_t (0[,]+∞)) ∈ Top
34	33	a1i 11	. . . . . . 7 ⊢ (𝐴 ∈ 𝐽 → ((ordTop‘ ≤ ) ↾_t (0[,]+∞)) ∈ Top)
35		ovex 7445	. . . . . . . 8 ⊢ (0(,]+∞) ∈ V
36	35	a1i 11	. . . . . . 7 ⊢ (𝐴 ∈ 𝐽 → (0(,]+∞) ∈ V)
37		pnfneige0.j	. . . . . . . . . 10 ⊢ 𝐽 = (TopOpen‘(ℝ^*_𝑠 ↾_s (0[,]+∞)))
38		xrge0topn 33218	. . . . . . . . . 10 ⊢ (TopOpen‘(ℝ^*_𝑠 ↾_s (0[,]+∞))) = ((ordTop‘ ≤ ) ↾_t (0[,]+∞))
39	37, 38	eqtri 2759	. . . . . . . . 9 ⊢ 𝐽 = ((ordTop‘ ≤ ) ↾_t (0[,]+∞))
40	39	eleq2i 2824	. . . . . . . 8 ⊢ (𝐴 ∈ 𝐽 ↔ 𝐴 ∈ ((ordTop‘ ≤ ) ↾_t (0[,]+∞)))
41	40	biimpi 215	. . . . . . 7 ⊢ (𝐴 ∈ 𝐽 → 𝐴 ∈ ((ordTop‘ ≤ ) ↾_t (0[,]+∞)))
42		elrestr 17379	. . . . . . 7 ⊢ ((((ordTop‘ ≤ ) ↾_t (0[,]+∞)) ∈ Top ∧ (0(,]+∞) ∈ V ∧ 𝐴 ∈ ((ordTop‘ ≤ ) ↾_t (0[,]+∞))) → (𝐴 ∩ (0(,]+∞)) ∈ (((ordTop‘ ≤ ) ↾_t (0[,]+∞)) ↾_t (0(,]+∞)))
43	34, 36, 41, 42	syl3anc 1370	. . . . . 6 ⊢ (𝐴 ∈ 𝐽 → (𝐴 ∩ (0(,]+∞)) ∈ (((ordTop‘ ≤ ) ↾_t (0[,]+∞)) ↾_t (0(,]+∞)))
44		letop 22931	. . . . . . 7 ⊢ (ordTop‘ ≤ ) ∈ Top
45		ovex 7445	. . . . . . 7 ⊢ (0[,]+∞) ∈ V
46		restabs 22890	. . . . . . 7 ⊢ (((ordTop‘ ≤ ) ∈ Top ∧ (0(,]+∞) ⊆ (0[,]+∞) ∧ (0[,]+∞) ∈ V) → (((ordTop‘ ≤ ) ↾_t (0[,]+∞)) ↾_t (0(,]+∞)) = ((ordTop‘ ≤ ) ↾_t (0(,]+∞)))
47	44, 14, 45, 46	mp3an 1460	. . . . . 6 ⊢ (((ordTop‘ ≤ ) ↾_t (0[,]+∞)) ↾_t (0(,]+∞)) = ((ordTop‘ ≤ ) ↾_t (0(,]+∞))
48	43, 47	eleqtrdi 2842	. . . . 5 ⊢ (𝐴 ∈ 𝐽 → (𝐴 ∩ (0(,]+∞)) ∈ ((ordTop‘ ≤ ) ↾_t (0(,]+∞)))
49	44	a1i 11	. . . . . 6 ⊢ (𝐴 ∈ 𝐽 → (ordTop‘ ≤ ) ∈ Top)
50		iocpnfordt 22940	. . . . . . 7 ⊢ (0(,]+∞) ∈ (ordTop‘ ≤ )
51	50	a1i 11	. . . . . 6 ⊢ (𝐴 ∈ 𝐽 → (0(,]+∞) ∈ (ordTop‘ ≤ ))
52		ssidd 4006	. . . . . 6 ⊢ (𝐴 ∈ 𝐽 → (0(,]+∞) ⊆ (0(,]+∞))
53		inss2 4230	. . . . . . 7 ⊢ (𝐴 ∩ (0(,]+∞)) ⊆ (0(,]+∞)
54	53	a1i 11	. . . . . 6 ⊢ (𝐴 ∈ 𝐽 → (𝐴 ∩ (0(,]+∞)) ⊆ (0(,]+∞))
55		restopnb 22900	. . . . . 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 1376	. . . . 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 480	. . 3 ⊢ ((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) → (𝐴 ∩ (0(,]+∞)) ∈ (ordTop‘ ≤ ))
59		simpr 484	. . . 4 ⊢ ((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) → +∞ ∈ 𝐴)
60		0ltpnf 13107	. . . . . 6 ⊢ 0 < +∞
61		ubioc1 13382	. . . . . 6 ⊢ ((0 ∈ ℝ^* ∧ +∞ ∈ ℝ^* ∧ 0 < +∞) → +∞ ∈ (0(,]+∞))
62	6, 8, 60, 61	mp3an 1460	. . . . 5 ⊢ +∞ ∈ (0(,]+∞)
63	62	a1i 11	. . . 4 ⊢ ((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) → +∞ ∈ (0(,]+∞))
64	59, 63	elind 4195	. . 3 ⊢ ((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) → +∞ ∈ (𝐴 ∩ (0(,]+∞)))
65		pnfnei 22945	. . 3 ⊢ (((𝐴 ∩ (0(,]+∞)) ∈ (ordTop‘ ≤ ) ∧ +∞ ∈ (𝐴 ∩ (0(,]+∞))) → ∃𝑦 ∈ ℝ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞)))
66	58, 64, 65	syl2anc 583	. 2 ⊢ ((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) → ∃𝑦 ∈ ℝ (𝑦(,]+∞) ⊆ (𝐴 ∩ (0(,]+∞)))
67	28, 66	r19.29a 3161	1 ⊢ ((𝐴 ∈ 𝐽 ∧ +∞ ∈ 𝐴) → ∃𝑥 ∈ ℝ (𝑥(,]+∞) ⊆ 𝐴)

Colors of variables: wff setvar class

Syntax hints: ¬ wn 3 → wi 4 ↔ wb 205 ∧ wa 395 = wceq 1540 ∈ wcel 2105 ∃wrex 3069 Vcvv 3473 ∩ cin 3948 ⊆ wss 3949 ifcif 4529 class class class wbr 5149 ‘cfv 6544 (class class class)co 7412 ℝcr 11112 0cc0 11113 +∞cpnf 11250 ℝ^*cxr 11252 < clt 11253 ≤ cle 11254 (,]cioc 13330 [,]cicc 13332 ↾_s cress 17178 ↾_t crest 17371 TopOpenctopn 17372 ordTopcordt 17450 ℝ^*_𝑠cxrs 17451 Topctop 22616 TopOnctopon 22633

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 1912 ax-6 1970 ax-7 2010 ax-8 2107 ax-9 2115 ax-10 2136 ax-11 2153 ax-12 2170 ax-ext 2702 ax-rep 5286 ax-sep 5300 ax-nul 5307 ax-pow 5364 ax-pr 5428 ax-un 7728 ax-cnex 11169 ax-resscn 11170 ax-1cn 11171 ax-icn 11172 ax-addcl 11173 ax-addrcl 11174 ax-mulcl 11175 ax-mulrcl 11176 ax-mulcom 11177 ax-addass 11178 ax-mulass 11179 ax-distr 11180 ax-i2m1 11181 ax-1ne0 11182 ax-1rid 11183 ax-rnegex 11184 ax-rrecex 11185 ax-cnre 11186 ax-pre-lttri 11187 ax-pre-lttrn 11188 ax-pre-ltadd 11189 ax-pre-mulgt0 11190

This theorem depends on definitions: df-bi 206 df-an 396 df-or 845 df-3or 1087 df-3an 1088 df-tru 1543 df-fal 1553 df-ex 1781 df-nf 1785 df-sb 2067 df-mo 2533 df-eu 2562 df-clab 2709 df-cleq 2723 df-clel 2809 df-nfc 2884 df-ne 2940 df-nel 3046 df-ral 3061 df-rex 3070 df-reu 3376 df-rab 3432 df-v 3475 df-sbc 3779 df-csb 3895 df-dif 3952 df-un 3954 df-in 3956 df-ss 3966 df-pss 3968 df-nul 4324 df-if 4530 df-pw 4605 df-sn 4630 df-pr 4632 df-tp 4634 df-op 4636 df-uni 4910 df-int 4952 df-iun 5000 df-br 5150 df-opab 5212 df-mpt 5233 df-tr 5267 df-id 5575 df-eprel 5581 df-po 5589 df-so 5590 df-fr 5632 df-we 5634 df-xp 5683 df-rel 5684 df-cnv 5685 df-co 5686 df-dm 5687 df-rn 5688 df-res 5689 df-ima 5690 df-pred 6301 df-ord 6368 df-on 6369 df-lim 6370 df-suc 6371 df-iota 6496 df-fun 6546 df-fn 6547 df-f 6548 df-f1 6549 df-fo 6550 df-f1o 6551 df-fv 6552 df-riota 7368 df-ov 7415 df-oprab 7416 df-mpo 7417 df-om 7859 df-1st 7978 df-2nd 7979 df-frecs 8269 df-wrecs 8300 df-recs 8374 df-rdg 8413 df-1o 8469 df-er 8706 df-en 8943 df-dom 8944 df-sdom 8945 df-fin 8946 df-fi 9409 df-pnf 11255 df-mnf 11256 df-xr 11257 df-ltxr 11258 df-le 11259 df-sub 11451 df-neg 11452 df-nn 12218 df-2 12280 df-3 12281 df-4 12282 df-5 12283 df-6 12284 df-7 12285 df-8 12286 df-9 12287 df-n0 12478 df-z 12564 df-dec 12683 df-uz 12828 df-ioo 13333 df-ioc 13334 df-ico 13335 df-icc 13336 df-fz 13490 df-struct 17085 df-sets 17102 df-slot 17120 df-ndx 17132 df-base 17150 df-ress 17179 df-plusg 17215 df-mulr 17216 df-tset 17221 df-ple 17222 df-ds 17224 df-rest 17373 df-topn 17374 df-topgen 17394 df-ordt 17452 df-xrs 17453 df-ps 18524 df-tsr 18525 df-top 22617 df-topon 22634 df-bases 22670

This theorem is referenced by: lmxrge0 33227

W3C validator