Theorem lo1bdd2 14255

Description: If an eventually bounded function is bounded on every interval 𝐴 ∩ (-∞, 𝑦) by a function 𝑀(𝑦), then the function is bounded on the whole domain. (Contributed by Mario Carneiro, 9-Apr-2016.)

Hypotheses

Ref	Expression
lo1bdd2.1	⊢ (𝜑 → 𝐴 ⊆ ℝ)
lo1bdd2.2	⊢ (𝜑 → 𝐶 ∈ ℝ)
lo1bdd2.3	⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ ℝ)
lo1bdd2.4	⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ 𝐵) ∈ ≤𝑂(1))
lo1bdd2.5	⊢ ((𝜑 ∧ (𝑦 ∈ ℝ ∧ 𝐶 ≤ 𝑦)) → 𝑀 ∈ ℝ)
lo1bdd2.6	⊢ (((𝜑 ∧ 𝑥 ∈ 𝐴) ∧ ((𝑦 ∈ ℝ ∧ 𝐶 ≤ 𝑦) ∧ 𝑥 < 𝑦)) → 𝐵 ≤ 𝑀)

Assertion

Ref	Expression
lo1bdd2	⊢ (𝜑 → ∃𝑚 ∈ ℝ ∀𝑥 ∈ 𝐴 𝐵 ≤ 𝑚)

Distinct variable groups:   𝑥,𝑚,𝑦,𝐴   𝐵,𝑚,𝑦   𝑥,𝐶,𝑦   𝜑,𝑥,𝑦   𝑚,𝑀,𝑥

Allowed substitution hints:   𝜑(𝑚)   𝐵(𝑥)   𝐶(𝑚)   𝑀(𝑦)

Proof of Theorem lo1bdd2

Dummy variable 𝑛 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		lo1bdd2.4	. . 3 ⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ 𝐵) ∈ ≤𝑂(1))
2		lo1bdd2.1	. . . 4 ⊢ (𝜑 → 𝐴 ⊆ ℝ)
3		lo1bdd2.3	. . . 4 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ ℝ)
4		lo1bdd2.2	. . . 4 ⊢ (𝜑 → 𝐶 ∈ ℝ)
5	2, 3, 4	ello1mpt2 14253	. . 3 ⊢ (𝜑 → ((𝑥 ∈ 𝐴 ↦ 𝐵) ∈ ≤𝑂(1) ↔ ∃𝑦 ∈ (𝐶[,)+∞)∃𝑛 ∈ ℝ ∀𝑥 ∈ 𝐴 (𝑦 ≤ 𝑥 → 𝐵 ≤ 𝑛)))
6	1, 5	mpbid 222	. 2 ⊢ (𝜑 → ∃𝑦 ∈ (𝐶[,)+∞)∃𝑛 ∈ ℝ ∀𝑥 ∈ 𝐴 (𝑦 ≤ 𝑥 → 𝐵 ≤ 𝑛))
7		elicopnf 12269	. . . . . . . . . . 11 ⊢ (𝐶 ∈ ℝ → (𝑦 ∈ (𝐶[,)+∞) ↔ (𝑦 ∈ ℝ ∧ 𝐶 ≤ 𝑦)))
8	4, 7	syl 17	. . . . . . . . . 10 ⊢ (𝜑 → (𝑦 ∈ (𝐶[,)+∞) ↔ (𝑦 ∈ ℝ ∧ 𝐶 ≤ 𝑦)))
9	8	biimpa 501	. . . . . . . . 9 ⊢ ((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) → (𝑦 ∈ ℝ ∧ 𝐶 ≤ 𝑦))
10		lo1bdd2.5	. . . . . . . . 9 ⊢ ((𝜑 ∧ (𝑦 ∈ ℝ ∧ 𝐶 ≤ 𝑦)) → 𝑀 ∈ ℝ)
11	9, 10	syldan 487	. . . . . . . 8 ⊢ ((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) → 𝑀 ∈ ℝ)
12	11	ad2antrr 762	. . . . . . 7 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ (𝑛 ∈ ℝ ∧ ∀𝑥 ∈ 𝐴 (𝑦 ≤ 𝑥 → 𝐵 ≤ 𝑛))) ∧ 𝑛 ≤ 𝑀) → 𝑀 ∈ ℝ)
13		simplrl 800	. . . . . . 7 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ (𝑛 ∈ ℝ ∧ ∀𝑥 ∈ 𝐴 (𝑦 ≤ 𝑥 → 𝐵 ≤ 𝑛))) ∧ ¬ 𝑛 ≤ 𝑀) → 𝑛 ∈ ℝ)
14	12, 13	ifclda 4120	. . . . . 6 ⊢ (((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ (𝑛 ∈ ℝ ∧ ∀𝑥 ∈ 𝐴 (𝑦 ≤ 𝑥 → 𝐵 ≤ 𝑛))) → if(𝑛 ≤ 𝑀, 𝑀, 𝑛) ∈ ℝ)
15	2	ad2antrr 762	. . . . . . . . . . . 12 ⊢ (((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) → 𝐴 ⊆ ℝ)
16	15	sselda 3603	. . . . . . . . . . 11 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ ℝ)
17	9	simpld 475	. . . . . . . . . . . 12 ⊢ ((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) → 𝑦 ∈ ℝ)
18	17	ad2antrr 762	. . . . . . . . . . 11 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) → 𝑦 ∈ ℝ)
19	16, 18	ltnled 10184	. . . . . . . . . 10 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) → (𝑥 < 𝑦 ↔ ¬ 𝑦 ≤ 𝑥))
20		lo1bdd2.6	. . . . . . . . . . . . . . . . 17 ⊢ (((𝜑 ∧ 𝑥 ∈ 𝐴) ∧ ((𝑦 ∈ ℝ ∧ 𝐶 ≤ 𝑦) ∧ 𝑥 < 𝑦)) → 𝐵 ≤ 𝑀)
21	20	expr 643	. . . . . . . . . . . . . . . 16 ⊢ (((𝜑 ∧ 𝑥 ∈ 𝐴) ∧ (𝑦 ∈ ℝ ∧ 𝐶 ≤ 𝑦)) → (𝑥 < 𝑦 → 𝐵 ≤ 𝑀))
22	21	an32s 846	. . . . . . . . . . . . . . 15 ⊢ (((𝜑 ∧ (𝑦 ∈ ℝ ∧ 𝐶 ≤ 𝑦)) ∧ 𝑥 ∈ 𝐴) → (𝑥 < 𝑦 → 𝐵 ≤ 𝑀))
23	22	ex 450	. . . . . . . . . . . . . 14 ⊢ ((𝜑 ∧ (𝑦 ∈ ℝ ∧ 𝐶 ≤ 𝑦)) → (𝑥 ∈ 𝐴 → (𝑥 < 𝑦 → 𝐵 ≤ 𝑀)))
24	9, 23	syldan 487	. . . . . . . . . . . . 13 ⊢ ((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) → (𝑥 ∈ 𝐴 → (𝑥 < 𝑦 → 𝐵 ≤ 𝑀)))
25	24	imp 445	. . . . . . . . . . . 12 ⊢ (((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑥 ∈ 𝐴) → (𝑥 < 𝑦 → 𝐵 ≤ 𝑀))
26	25	adantlr 751	. . . . . . . . . . 11 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) → (𝑥 < 𝑦 → 𝐵 ≤ 𝑀))
27		simplr 792	. . . . . . . . . . . . 13 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) → 𝑛 ∈ ℝ)
28	11	ad2antrr 762	. . . . . . . . . . . . 13 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) → 𝑀 ∈ ℝ)
29		max2 12018	. . . . . . . . . . . . 13 ⊢ ((𝑛 ∈ ℝ ∧ 𝑀 ∈ ℝ) → 𝑀 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛))
30	27, 28, 29	syl2anc 693	. . . . . . . . . . . 12 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) → 𝑀 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛))
31		simpll 790	. . . . . . . . . . . . . 14 ⊢ (((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) → 𝜑)
32	31, 3	sylan 488	. . . . . . . . . . . . 13 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ ℝ)
33	11	ad3antrrr 766	. . . . . . . . . . . . . 14 ⊢ (((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) ∧ 𝑛 ≤ 𝑀) → 𝑀 ∈ ℝ)
34		simpllr 799	. . . . . . . . . . . . . 14 ⊢ (((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) ∧ ¬ 𝑛 ≤ 𝑀) → 𝑛 ∈ ℝ)
35	33, 34	ifclda 4120	. . . . . . . . . . . . 13 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) → if(𝑛 ≤ 𝑀, 𝑀, 𝑛) ∈ ℝ)
36		letr 10131	. . . . . . . . . . . . 13 ⊢ ((𝐵 ∈ ℝ ∧ 𝑀 ∈ ℝ ∧ if(𝑛 ≤ 𝑀, 𝑀, 𝑛) ∈ ℝ) → ((𝐵 ≤ 𝑀 ∧ 𝑀 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛)) → 𝐵 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛)))
37	32, 28, 35, 36	syl3anc 1326	. . . . . . . . . . . 12 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) → ((𝐵 ≤ 𝑀 ∧ 𝑀 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛)) → 𝐵 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛)))
38	30, 37	mpan2d 710	. . . . . . . . . . 11 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) → (𝐵 ≤ 𝑀 → 𝐵 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛)))
39	26, 38	syld 47	. . . . . . . . . 10 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) → (𝑥 < 𝑦 → 𝐵 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛)))
40	19, 39	sylbird 250	. . . . . . . . 9 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) → (¬ 𝑦 ≤ 𝑥 → 𝐵 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛)))
41		max1 12016	. . . . . . . . . . 11 ⊢ ((𝑛 ∈ ℝ ∧ 𝑀 ∈ ℝ) → 𝑛 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛))
42	27, 28, 41	syl2anc 693	. . . . . . . . . 10 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) → 𝑛 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛))
43		letr 10131	. . . . . . . . . . 11 ⊢ ((𝐵 ∈ ℝ ∧ 𝑛 ∈ ℝ ∧ if(𝑛 ≤ 𝑀, 𝑀, 𝑛) ∈ ℝ) → ((𝐵 ≤ 𝑛 ∧ 𝑛 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛)) → 𝐵 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛)))
44	32, 27, 35, 43	syl3anc 1326	. . . . . . . . . 10 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) → ((𝐵 ≤ 𝑛 ∧ 𝑛 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛)) → 𝐵 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛)))
45	42, 44	mpan2d 710	. . . . . . . . 9 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) → (𝐵 ≤ 𝑛 → 𝐵 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛)))
46	40, 45	jad 174	. . . . . . . 8 ⊢ ((((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) ∧ 𝑥 ∈ 𝐴) → ((𝑦 ≤ 𝑥 → 𝐵 ≤ 𝑛) → 𝐵 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛)))
47	46	ralimdva 2962	. . . . . . 7 ⊢ (((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) → (∀𝑥 ∈ 𝐴 (𝑦 ≤ 𝑥 → 𝐵 ≤ 𝑛) → ∀𝑥 ∈ 𝐴 𝐵 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛)))
48	47	impr 649	. . . . . 6 ⊢ (((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ (𝑛 ∈ ℝ ∧ ∀𝑥 ∈ 𝐴 (𝑦 ≤ 𝑥 → 𝐵 ≤ 𝑛))) → ∀𝑥 ∈ 𝐴 𝐵 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛))
49		breq2 4657	. . . . . . . 8 ⊢ (𝑚 = if(𝑛 ≤ 𝑀, 𝑀, 𝑛) → (𝐵 ≤ 𝑚 ↔ 𝐵 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛)))
50	49	ralbidv 2986	. . . . . . 7 ⊢ (𝑚 = if(𝑛 ≤ 𝑀, 𝑀, 𝑛) → (∀𝑥 ∈ 𝐴 𝐵 ≤ 𝑚 ↔ ∀𝑥 ∈ 𝐴 𝐵 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛)))
51	50	rspcev 3309	. . . . . 6 ⊢ ((if(𝑛 ≤ 𝑀, 𝑀, 𝑛) ∈ ℝ ∧ ∀𝑥 ∈ 𝐴 𝐵 ≤ if(𝑛 ≤ 𝑀, 𝑀, 𝑛)) → ∃𝑚 ∈ ℝ ∀𝑥 ∈ 𝐴 𝐵 ≤ 𝑚)
52	14, 48, 51	syl2anc 693	. . . . 5 ⊢ (((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ (𝑛 ∈ ℝ ∧ ∀𝑥 ∈ 𝐴 (𝑦 ≤ 𝑥 → 𝐵 ≤ 𝑛))) → ∃𝑚 ∈ ℝ ∀𝑥 ∈ 𝐴 𝐵 ≤ 𝑚)
53	52	expr 643	. . . 4 ⊢ (((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) ∧ 𝑛 ∈ ℝ) → (∀𝑥 ∈ 𝐴 (𝑦 ≤ 𝑥 → 𝐵 ≤ 𝑛) → ∃𝑚 ∈ ℝ ∀𝑥 ∈ 𝐴 𝐵 ≤ 𝑚))
54	53	rexlimdva 3031	. . 3 ⊢ ((𝜑 ∧ 𝑦 ∈ (𝐶[,)+∞)) → (∃𝑛 ∈ ℝ ∀𝑥 ∈ 𝐴 (𝑦 ≤ 𝑥 → 𝐵 ≤ 𝑛) → ∃𝑚 ∈ ℝ ∀𝑥 ∈ 𝐴 𝐵 ≤ 𝑚))
55	54	rexlimdva 3031	. 2 ⊢ (𝜑 → (∃𝑦 ∈ (𝐶[,)+∞)∃𝑛 ∈ ℝ ∀𝑥 ∈ 𝐴 (𝑦 ≤ 𝑥 → 𝐵 ≤ 𝑛) → ∃𝑚 ∈ ℝ ∀𝑥 ∈ 𝐴 𝐵 ≤ 𝑚))
56	6, 55	mpd 15	1 ⊢ (𝜑 → ∃𝑚 ∈ ℝ ∀𝑥 ∈ 𝐴 𝐵 ≤ 𝑚)

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 196   ∧ wa 384   = wceq 1483   ∈ wcel 1990  ∀wral 2912  ∃wrex 2913   ⊆ wss 3574  ifcif 4086   class class class wbr 4653   ↦ cmpt 4729  (class class class)co 6650  ℝcr 9935  +∞cpnf 10071   < clt 10074   ≤ cle 10075  [,)cico 12177  ≤𝑂(1)clo1 14218

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-8 1992  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602  ax-sep 4781  ax-nul 4789  ax-pow 4843  ax-pr 4906  ax-un 6949  ax-cnex 9992  ax-resscn 9993  ax-pre-lttri 10010  ax-pre-lttrn 10011

This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-3or 1038  df-3an 1039  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-eu 2474  df-mo 2475  df-clab 2609  df-cleq 2615  df-clel 2618  df-nfc 2753  df-ne 2795  df-nel 2898  df-ral 2917  df-rex 2918  df-rab 2921  df-v 3202  df-sbc 3436  df-csb 3534  df-dif 3577  df-un 3579  df-in 3581  df-ss 3588  df-nul 3916  df-if 4087  df-pw 4160  df-sn 4178  df-pr 4180  df-op 4184  df-uni 4437  df-br 4654  df-opab 4713  df-mpt 4730  df-id 5024  df-po 5035  df-so 5036  df-xp 5120  df-rel 5121  df-cnv 5122  df-co 5123  df-dm 5124  df-rn 5125  df-res 5126  df-ima 5127  df-iota 5851  df-fun 5890  df-fn 5891  df-f 5892  df-f1 5893  df-fo 5894  df-f1o 5895  df-fv 5896  df-ov 6653  df-oprab 6654  df-mpt2 6655  df-er 7742  df-pm 7860  df-en 7956  df-dom 7957  df-sdom 7958  df-pnf 10076  df-mnf 10077  df-xr 10078  df-ltxr 10079  df-le 10080  df-ico 12181  df-lo1 14222

This theorem is referenced by:  lo1bddrp  14256  o1bdd2  14272