Theorem rexico 15238

Description: Restrict the base of an upper real quantifier to an upper real set. (Contributed by Mario Carneiro, 12-May-2016.)

Assertion

Ref	Expression
rexico	⊢ ((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) → (∃𝑗 ∈ (𝐵[,)+∞)∀𝑘 ∈ 𝐴 (𝑗 ≤ 𝑘 → 𝜑) ↔ ∃𝑗 ∈ ℝ ∀𝑘 ∈ 𝐴 (𝑗 ≤ 𝑘 → 𝜑)))

Distinct variable groups:   𝑗,𝑘,𝐴   𝐵,𝑗,𝑘   𝜑,𝑗

Allowed substitution hint:   𝜑(𝑘)

Proof of Theorem rexico

Dummy variable 𝑛 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		simpr 485	. . . 4 ⊢ ((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) → 𝐵 ∈ ℝ)
2		pnfxr 11209	. . . 4 ⊢ +∞ ∈ ℝ*
3		icossre 13345	. . . 4 ⊢ ((𝐵 ∈ ℝ ∧ +∞ ∈ ℝ*) → (𝐵[,)+∞) ⊆ ℝ)
4	1, 2, 3	sylancl 586	. . 3 ⊢ ((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) → (𝐵[,)+∞) ⊆ ℝ)
5		ssrexv 4011	. . 3 ⊢ ((𝐵[,)+∞) ⊆ ℝ → (∃𝑗 ∈ (𝐵[,)+∞)∀𝑘 ∈ 𝐴 (𝑗 ≤ 𝑘 → 𝜑) → ∃𝑗 ∈ ℝ ∀𝑘 ∈ 𝐴 (𝑗 ≤ 𝑘 → 𝜑)))
6	4, 5	syl 17	. 2 ⊢ ((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) → (∃𝑗 ∈ (𝐵[,)+∞)∀𝑘 ∈ 𝐴 (𝑗 ≤ 𝑘 → 𝜑) → ∃𝑗 ∈ ℝ ∀𝑘 ∈ 𝐴 (𝑗 ≤ 𝑘 → 𝜑)))
7		simpr 485	. . . . . . 7 ⊢ (((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑗 ∈ ℝ) → 𝑗 ∈ ℝ)
8		simplr 767	. . . . . . 7 ⊢ (((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑗 ∈ ℝ) → 𝐵 ∈ ℝ)
9	7, 8	ifcld 4532	. . . . . 6 ⊢ (((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑗 ∈ ℝ) → if(𝐵 ≤ 𝑗, 𝑗, 𝐵) ∈ ℝ)
10		max1 13104	. . . . . . 7 ⊢ ((𝐵 ∈ ℝ ∧ 𝑗 ∈ ℝ) → 𝐵 ≤ if(𝐵 ≤ 𝑗, 𝑗, 𝐵))
11	10	adantll 712	. . . . . 6 ⊢ (((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑗 ∈ ℝ) → 𝐵 ≤ if(𝐵 ≤ 𝑗, 𝑗, 𝐵))
12		elicopnf 13362	. . . . . . 7 ⊢ (𝐵 ∈ ℝ → (if(𝐵 ≤ 𝑗, 𝑗, 𝐵) ∈ (𝐵[,)+∞) ↔ (if(𝐵 ≤ 𝑗, 𝑗, 𝐵) ∈ ℝ ∧ 𝐵 ≤ if(𝐵 ≤ 𝑗, 𝑗, 𝐵))))
13	12	ad2antlr 725	. . . . . 6 ⊢ (((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑗 ∈ ℝ) → (if(𝐵 ≤ 𝑗, 𝑗, 𝐵) ∈ (𝐵[,)+∞) ↔ (if(𝐵 ≤ 𝑗, 𝑗, 𝐵) ∈ ℝ ∧ 𝐵 ≤ if(𝐵 ≤ 𝑗, 𝑗, 𝐵))))
14	9, 11, 13	mpbir2and 711	. . . . 5 ⊢ (((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑗 ∈ ℝ) → if(𝐵 ≤ 𝑗, 𝑗, 𝐵) ∈ (𝐵[,)+∞))
15		simpllr 774	. . . . . . . . 9 ⊢ ((((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑗 ∈ ℝ) ∧ 𝑘 ∈ 𝐴) → 𝐵 ∈ ℝ)
16		simplr 767	. . . . . . . . 9 ⊢ ((((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑗 ∈ ℝ) ∧ 𝑘 ∈ 𝐴) → 𝑗 ∈ ℝ)
17		simpll 765	. . . . . . . . . 10 ⊢ (((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑗 ∈ ℝ) → 𝐴 ⊆ ℝ)
18	17	sselda 3944	. . . . . . . . 9 ⊢ ((((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑗 ∈ ℝ) ∧ 𝑘 ∈ 𝐴) → 𝑘 ∈ ℝ)
19		maxle 13110	. . . . . . . . 9 ⊢ ((𝐵 ∈ ℝ ∧ 𝑗 ∈ ℝ ∧ 𝑘 ∈ ℝ) → (if(𝐵 ≤ 𝑗, 𝑗, 𝐵) ≤ 𝑘 ↔ (𝐵 ≤ 𝑘 ∧ 𝑗 ≤ 𝑘)))
20	15, 16, 18, 19	syl3anc 1371	. . . . . . . 8 ⊢ ((((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑗 ∈ ℝ) ∧ 𝑘 ∈ 𝐴) → (if(𝐵 ≤ 𝑗, 𝑗, 𝐵) ≤ 𝑘 ↔ (𝐵 ≤ 𝑘 ∧ 𝑗 ≤ 𝑘)))
21		simpr 485	. . . . . . . 8 ⊢ ((𝐵 ≤ 𝑘 ∧ 𝑗 ≤ 𝑘) → 𝑗 ≤ 𝑘)
22	20, 21	syl6bi 252	. . . . . . 7 ⊢ ((((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑗 ∈ ℝ) ∧ 𝑘 ∈ 𝐴) → (if(𝐵 ≤ 𝑗, 𝑗, 𝐵) ≤ 𝑘 → 𝑗 ≤ 𝑘))
23	22	imim1d 82	. . . . . 6 ⊢ ((((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑗 ∈ ℝ) ∧ 𝑘 ∈ 𝐴) → ((𝑗 ≤ 𝑘 → 𝜑) → (if(𝐵 ≤ 𝑗, 𝑗, 𝐵) ≤ 𝑘 → 𝜑)))
24	23	ralimdva 3164	. . . . 5 ⊢ (((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑗 ∈ ℝ) → (∀𝑘 ∈ 𝐴 (𝑗 ≤ 𝑘 → 𝜑) → ∀𝑘 ∈ 𝐴 (if(𝐵 ≤ 𝑗, 𝑗, 𝐵) ≤ 𝑘 → 𝜑)))
25		breq1 5108	. . . . . 6 ⊢ (𝑛 = if(𝐵 ≤ 𝑗, 𝑗, 𝐵) → (𝑛 ≤ 𝑘 ↔ if(𝐵 ≤ 𝑗, 𝑗, 𝐵) ≤ 𝑘))
26	25	rspceaimv 3585	. . . . 5 ⊢ ((if(𝐵 ≤ 𝑗, 𝑗, 𝐵) ∈ (𝐵[,)+∞) ∧ ∀𝑘 ∈ 𝐴 (if(𝐵 ≤ 𝑗, 𝑗, 𝐵) ≤ 𝑘 → 𝜑)) → ∃𝑛 ∈ (𝐵[,)+∞)∀𝑘 ∈ 𝐴 (𝑛 ≤ 𝑘 → 𝜑))
27	14, 24, 26	syl6an 682	. . . 4 ⊢ (((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑗 ∈ ℝ) → (∀𝑘 ∈ 𝐴 (𝑗 ≤ 𝑘 → 𝜑) → ∃𝑛 ∈ (𝐵[,)+∞)∀𝑘 ∈ 𝐴 (𝑛 ≤ 𝑘 → 𝜑)))
28	27	rexlimdva 3152	. . 3 ⊢ ((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) → (∃𝑗 ∈ ℝ ∀𝑘 ∈ 𝐴 (𝑗 ≤ 𝑘 → 𝜑) → ∃𝑛 ∈ (𝐵[,)+∞)∀𝑘 ∈ 𝐴 (𝑛 ≤ 𝑘 → 𝜑)))
29		breq1 5108	. . . . . 6 ⊢ (𝑛 = 𝑗 → (𝑛 ≤ 𝑘 ↔ 𝑗 ≤ 𝑘))
30	29	imbi1d 341	. . . . 5 ⊢ (𝑛 = 𝑗 → ((𝑛 ≤ 𝑘 → 𝜑) ↔ (𝑗 ≤ 𝑘 → 𝜑)))
31	30	ralbidv 3174	. . . 4 ⊢ (𝑛 = 𝑗 → (∀𝑘 ∈ 𝐴 (𝑛 ≤ 𝑘 → 𝜑) ↔ ∀𝑘 ∈ 𝐴 (𝑗 ≤ 𝑘 → 𝜑)))
32	31	cbvrexvw 3226	. . 3 ⊢ (∃𝑛 ∈ (𝐵[,)+∞)∀𝑘 ∈ 𝐴 (𝑛 ≤ 𝑘 → 𝜑) ↔ ∃𝑗 ∈ (𝐵[,)+∞)∀𝑘 ∈ 𝐴 (𝑗 ≤ 𝑘 → 𝜑))
33	28, 32	syl6ib 250	. 2 ⊢ ((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) → (∃𝑗 ∈ ℝ ∀𝑘 ∈ 𝐴 (𝑗 ≤ 𝑘 → 𝜑) → ∃𝑗 ∈ (𝐵[,)+∞)∀𝑘 ∈ 𝐴 (𝑗 ≤ 𝑘 → 𝜑)))
34	6, 33	impbid 211	1 ⊢ ((𝐴 ⊆ ℝ ∧ 𝐵 ∈ ℝ) → (∃𝑗 ∈ (𝐵[,)+∞)∀𝑘 ∈ 𝐴 (𝑗 ≤ 𝑘 → 𝜑) ↔ ∃𝑗 ∈ ℝ ∀𝑘 ∈ 𝐴 (𝑗 ≤ 𝑘 → 𝜑)))

Syntax hints:   → wi 4   ↔ wb 205   ∧ wa 396   ∈ wcel 2106  ∀wral 3064  ∃wrex 3073   ⊆ wss 3910  ifcif 4486   class class class wbr 5105  (class class class)co 7357  ℝcr 11050  +∞cpnf 11186  ℝ^*cxr 11188   ≤ cle 11190  [,)cico 13266

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1797  ax-4 1811  ax-5 1913  ax-6 1971  ax-7 2011  ax-8 2108  ax-9 2116  ax-10 2137  ax-11 2154  ax-12 2171  ax-ext 2707  ax-sep 5256  ax-nul 5263  ax-pow 5320  ax-pr 5384  ax-un 7672  ax-cnex 11107  ax-resscn 11108  ax-pre-lttri 11125  ax-pre-lttrn 11126

This theorem depends on definitions:  df-bi 206  df-an 397  df-or 846  df-3or 1088  df-3an 1089  df-tru 1544  df-fal 1554  df-ex 1782  df-nf 1786  df-sb 2068  df-mo 2538  df-eu 2567  df-clab 2714  df-cleq 2728  df-clel 2814  df-nfc 2889  df-ne 2944  df-nel 3050  df-ral 3065  df-rex 3074  df-rab 3408  df-v 3447  df-sbc 3740  df-csb 3856  df-dif 3913  df-un 3915  df-in 3917  df-ss 3927  df-nul 4283  df-if 4487  df-pw 4562  df-sn 4587  df-pr 4589  df-op 4593  df-uni 4866  df-br 5106  df-opab 5168  df-mpt 5189  df-id 5531  df-po 5545  df-so 5546  df-xp 5639  df-rel 5640  df-cnv 5641  df-co 5642  df-dm 5643  df-rn 5644  df-res 5645  df-ima 5646  df-iota 6448  df-fun 6498  df-fn 6499  df-f 6500  df-f1 6501  df-fo 6502  df-f1o 6503  df-fv 6504  df-ov 7360  df-oprab 7361  df-mpo 7362  df-er 8648  df-en 8884  df-dom 8885  df-sdom 8886  df-pnf 11191  df-mnf 11192  df-xr 11193  df-ltxr 11194  df-le 11195  df-ico 13270

This theorem is referenced by:  rlimi2  15396  ello1mpt2  15404  dvfsumrlim  25395