qtopbaslem - Metamath Proof Explorer

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Theorem qtopbaslem 24779

Description: The set of open intervals with endpoints in a subset forms a basis for a topology. (Contributed by Mario Carneiro, 17-Jun-2014.)

**Hypothesis**
Ref	Expression
qtopbas.1	⊢ 𝑆 ⊆ ℝ^*

**Assertion**
Ref	Expression
qtopbaslem	⊢ ((,) “ (𝑆 × 𝑆)) ∈ TopBases

Proof of Theorem qtopbaslem Dummy variables 𝑢 𝑡 𝑣 𝑤 𝑥 𝑦 𝑧 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		iooex 13410	. . 3 ⊢ (,) ∈ V
2	1	imaex 7936	. 2 ⊢ ((,) “ (𝑆 × 𝑆)) ∈ V
3		qtopbas.1	. . . . . . . . 9 ⊢ 𝑆 ⊆ ℝ^*
4	3	sseli 3979	. . . . . . . 8 ⊢ (𝑧 ∈ 𝑆 → 𝑧 ∈ ℝ^*)
5	3	sseli 3979	. . . . . . . 8 ⊢ (𝑤 ∈ 𝑆 → 𝑤 ∈ ℝ^*)
6	4, 5	anim12i 613	. . . . . . 7 ⊢ ((𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) → (𝑧 ∈ ℝ^* ∧ 𝑤 ∈ ℝ^*))
7	3	sseli 3979	. . . . . . . 8 ⊢ (𝑣 ∈ 𝑆 → 𝑣 ∈ ℝ^*)
8	3	sseli 3979	. . . . . . . 8 ⊢ (𝑢 ∈ 𝑆 → 𝑢 ∈ ℝ^*)
9	7, 8	anim12i 613	. . . . . . 7 ⊢ ((𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆) → (𝑣 ∈ ℝ^* ∧ 𝑢 ∈ ℝ^*))
10		iooin 13421	. . . . . . 7 ⊢ (((𝑧 ∈ ℝ^* ∧ 𝑤 ∈ ℝ^) ∧ (𝑣 ∈ ℝ^ ∧ 𝑢 ∈ ℝ^*)) → ((𝑧(,)𝑤) ∩ (𝑣(,)𝑢)) = (if(𝑧 ≤ 𝑣, 𝑣, 𝑧)(,)if(𝑤 ≤ 𝑢, 𝑤, 𝑢)))
11	6, 9, 10	syl2an 596	. . . . . 6 ⊢ (((𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → ((𝑧(,)𝑤) ∩ (𝑣(,)𝑢)) = (if(𝑧 ≤ 𝑣, 𝑣, 𝑧)(,)if(𝑤 ≤ 𝑢, 𝑤, 𝑢)))
12		ifcl 4571	. . . . . . . . 9 ⊢ ((𝑣 ∈ 𝑆 ∧ 𝑧 ∈ 𝑆) → if(𝑧 ≤ 𝑣, 𝑣, 𝑧) ∈ 𝑆)
13	12	ancoms 458	. . . . . . . 8 ⊢ ((𝑧 ∈ 𝑆 ∧ 𝑣 ∈ 𝑆) → if(𝑧 ≤ 𝑣, 𝑣, 𝑧) ∈ 𝑆)
14		ifcl 4571	. . . . . . . 8 ⊢ ((𝑤 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆) → if(𝑤 ≤ 𝑢, 𝑤, 𝑢) ∈ 𝑆)
15		df-ov 7434	. . . . . . . . 9 ⊢ (if(𝑧 ≤ 𝑣, 𝑣, 𝑧)(,)if(𝑤 ≤ 𝑢, 𝑤, 𝑢)) = ((,)‘⟨if(𝑧 ≤ 𝑣, 𝑣, 𝑧), if(𝑤 ≤ 𝑢, 𝑤, 𝑢)⟩)
16		opelxpi 5722	. . . . . . . . . 10 ⊢ ((if(𝑧 ≤ 𝑣, 𝑣, 𝑧) ∈ 𝑆 ∧ if(𝑤 ≤ 𝑢, 𝑤, 𝑢) ∈ 𝑆) → ⟨if(𝑧 ≤ 𝑣, 𝑣, 𝑧), if(𝑤 ≤ 𝑢, 𝑤, 𝑢)⟩ ∈ (𝑆 × 𝑆))
17		ioof 13487	. . . . . . . . . . . 12 ⊢ (,):(ℝ^* × ℝ^*)⟶𝒫 ℝ
18		ffun 6739	. . . . . . . . . . . 12 ⊢ ((,):(ℝ^* × ℝ^*)⟶𝒫 ℝ → Fun (,))
19	17, 18	ax-mp 5	. . . . . . . . . . 11 ⊢ Fun (,)
20		xpss12 5700	. . . . . . . . . . . . 13 ⊢ ((𝑆 ⊆ ℝ^* ∧ 𝑆 ⊆ ℝ^) → (𝑆 × 𝑆) ⊆ (ℝ^ × ℝ^*))
21	3, 3, 20	mp2an 692	. . . . . . . . . . . 12 ⊢ (𝑆 × 𝑆) ⊆ (ℝ^* × ℝ^*)
22	17	fdmi 6747	. . . . . . . . . . . 12 ⊢ dom (,) = (ℝ^* × ℝ^*)
23	21, 22	sseqtrri 4033	. . . . . . . . . . 11 ⊢ (𝑆 × 𝑆) ⊆ dom (,)
24		funfvima2 7251	. . . . . . . . . . 11 ⊢ ((Fun (,) ∧ (𝑆 × 𝑆) ⊆ dom (,)) → (⟨if(𝑧 ≤ 𝑣, 𝑣, 𝑧), if(𝑤 ≤ 𝑢, 𝑤, 𝑢)⟩ ∈ (𝑆 × 𝑆) → ((,)‘⟨if(𝑧 ≤ 𝑣, 𝑣, 𝑧), if(𝑤 ≤ 𝑢, 𝑤, 𝑢)⟩) ∈ ((,) “ (𝑆 × 𝑆))))
25	19, 23, 24	mp2an 692	. . . . . . . . . 10 ⊢ (⟨if(𝑧 ≤ 𝑣, 𝑣, 𝑧), if(𝑤 ≤ 𝑢, 𝑤, 𝑢)⟩ ∈ (𝑆 × 𝑆) → ((,)‘⟨if(𝑧 ≤ 𝑣, 𝑣, 𝑧), if(𝑤 ≤ 𝑢, 𝑤, 𝑢)⟩) ∈ ((,) “ (𝑆 × 𝑆)))
26	16, 25	syl 17	. . . . . . . . 9 ⊢ ((if(𝑧 ≤ 𝑣, 𝑣, 𝑧) ∈ 𝑆 ∧ if(𝑤 ≤ 𝑢, 𝑤, 𝑢) ∈ 𝑆) → ((,)‘⟨if(𝑧 ≤ 𝑣, 𝑣, 𝑧), if(𝑤 ≤ 𝑢, 𝑤, 𝑢)⟩) ∈ ((,) “ (𝑆 × 𝑆)))
27	15, 26	eqeltrid 2845	. . . . . . . 8 ⊢ ((if(𝑧 ≤ 𝑣, 𝑣, 𝑧) ∈ 𝑆 ∧ if(𝑤 ≤ 𝑢, 𝑤, 𝑢) ∈ 𝑆) → (if(𝑧 ≤ 𝑣, 𝑣, 𝑧)(,)if(𝑤 ≤ 𝑢, 𝑤, 𝑢)) ∈ ((,) “ (𝑆 × 𝑆)))
28	13, 14, 27	syl2an 596	. . . . . . 7 ⊢ (((𝑧 ∈ 𝑆 ∧ 𝑣 ∈ 𝑆) ∧ (𝑤 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → (if(𝑧 ≤ 𝑣, 𝑣, 𝑧)(,)if(𝑤 ≤ 𝑢, 𝑤, 𝑢)) ∈ ((,) “ (𝑆 × 𝑆)))
29	28	an4s 660	. . . . . 6 ⊢ (((𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → (if(𝑧 ≤ 𝑣, 𝑣, 𝑧)(,)if(𝑤 ≤ 𝑢, 𝑤, 𝑢)) ∈ ((,) “ (𝑆 × 𝑆)))
30	11, 29	eqeltrd 2841	. . . . 5 ⊢ (((𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) ∧ (𝑣 ∈ 𝑆 ∧ 𝑢 ∈ 𝑆)) → ((𝑧(,)𝑤) ∩ (𝑣(,)𝑢)) ∈ ((,) “ (𝑆 × 𝑆)))
31	30	ralrimivva 3202	. . . 4 ⊢ ((𝑧 ∈ 𝑆 ∧ 𝑤 ∈ 𝑆) → ∀𝑣 ∈ 𝑆 ∀𝑢 ∈ 𝑆 ((𝑧(,)𝑤) ∩ (𝑣(,)𝑢)) ∈ ((,) “ (𝑆 × 𝑆)))
32	31	rgen2 3199	. . 3 ⊢ ∀𝑧 ∈ 𝑆 ∀𝑤 ∈ 𝑆 ∀𝑣 ∈ 𝑆 ∀𝑢 ∈ 𝑆 ((𝑧(,)𝑤) ∩ (𝑣(,)𝑢)) ∈ ((,) “ (𝑆 × 𝑆))
33		ffn 6736	. . . . . 6 ⊢ ((,):(ℝ^* × ℝ^)⟶𝒫 ℝ → (,) Fn (ℝ^ × ℝ^*))
34	17, 33	ax-mp 5	. . . . 5 ⊢ (,) Fn (ℝ^* × ℝ^*)
35		ineq1 4213	. . . . . . . 8 ⊢ (𝑥 = ((,)‘𝑡) → (𝑥 ∩ 𝑦) = (((,)‘𝑡) ∩ 𝑦))
36	35	eleq1d 2826	. . . . . . 7 ⊢ (𝑥 = ((,)‘𝑡) → ((𝑥 ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆)) ↔ (((,)‘𝑡) ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆))))
37	36	ralbidv 3178	. . . . . 6 ⊢ (𝑥 = ((,)‘𝑡) → (∀𝑦 ∈ ((,) “ (𝑆 × 𝑆))(𝑥 ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆)) ↔ ∀𝑦 ∈ ((,) “ (𝑆 × 𝑆))(((,)‘𝑡) ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆))))
38	37	ralima 7257	. . . . 5 ⊢ (((,) Fn (ℝ^* × ℝ^) ∧ (𝑆 × 𝑆) ⊆ (ℝ^ × ℝ^*)) → (∀𝑥 ∈ ((,) “ (𝑆 × 𝑆))∀𝑦 ∈ ((,) “ (𝑆 × 𝑆))(𝑥 ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆)) ↔ ∀𝑡 ∈ (𝑆 × 𝑆)∀𝑦 ∈ ((,) “ (𝑆 × 𝑆))(((,)‘𝑡) ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆))))
39	34, 21, 38	mp2an 692	. . . 4 ⊢ (∀𝑥 ∈ ((,) “ (𝑆 × 𝑆))∀𝑦 ∈ ((,) “ (𝑆 × 𝑆))(𝑥 ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆)) ↔ ∀𝑡 ∈ (𝑆 × 𝑆)∀𝑦 ∈ ((,) “ (𝑆 × 𝑆))(((,)‘𝑡) ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆)))
40		fveq2 6906	. . . . . . . . . 10 ⊢ (𝑡 = ⟨𝑧, 𝑤⟩ → ((,)‘𝑡) = ((,)‘⟨𝑧, 𝑤⟩))
41		df-ov 7434	. . . . . . . . . 10 ⊢ (𝑧(,)𝑤) = ((,)‘⟨𝑧, 𝑤⟩)
42	40, 41	eqtr4di 2795	. . . . . . . . 9 ⊢ (𝑡 = ⟨𝑧, 𝑤⟩ → ((,)‘𝑡) = (𝑧(,)𝑤))
43	42	ineq1d 4219	. . . . . . . 8 ⊢ (𝑡 = ⟨𝑧, 𝑤⟩ → (((,)‘𝑡) ∩ 𝑦) = ((𝑧(,)𝑤) ∩ 𝑦))
44	43	eleq1d 2826	. . . . . . 7 ⊢ (𝑡 = ⟨𝑧, 𝑤⟩ → ((((,)‘𝑡) ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆)) ↔ ((𝑧(,)𝑤) ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆))))
45	44	ralbidv 3178	. . . . . 6 ⊢ (𝑡 = ⟨𝑧, 𝑤⟩ → (∀𝑦 ∈ ((,) “ (𝑆 × 𝑆))(((,)‘𝑡) ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆)) ↔ ∀𝑦 ∈ ((,) “ (𝑆 × 𝑆))((𝑧(,)𝑤) ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆))))
46		ineq2 4214	. . . . . . . . . 10 ⊢ (𝑦 = ((,)‘𝑡) → ((𝑧(,)𝑤) ∩ 𝑦) = ((𝑧(,)𝑤) ∩ ((,)‘𝑡)))
47	46	eleq1d 2826	. . . . . . . . 9 ⊢ (𝑦 = ((,)‘𝑡) → (((𝑧(,)𝑤) ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆)) ↔ ((𝑧(,)𝑤) ∩ ((,)‘𝑡)) ∈ ((,) “ (𝑆 × 𝑆))))
48	47	ralima 7257	. . . . . . . 8 ⊢ (((,) Fn (ℝ^* × ℝ^) ∧ (𝑆 × 𝑆) ⊆ (ℝ^ × ℝ^*)) → (∀𝑦 ∈ ((,) “ (𝑆 × 𝑆))((𝑧(,)𝑤) ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆)) ↔ ∀𝑡 ∈ (𝑆 × 𝑆)((𝑧(,)𝑤) ∩ ((,)‘𝑡)) ∈ ((,) “ (𝑆 × 𝑆))))
49	34, 21, 48	mp2an 692	. . . . . . 7 ⊢ (∀𝑦 ∈ ((,) “ (𝑆 × 𝑆))((𝑧(,)𝑤) ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆)) ↔ ∀𝑡 ∈ (𝑆 × 𝑆)((𝑧(,)𝑤) ∩ ((,)‘𝑡)) ∈ ((,) “ (𝑆 × 𝑆)))
50		fveq2 6906	. . . . . . . . . . 11 ⊢ (𝑡 = ⟨𝑣, 𝑢⟩ → ((,)‘𝑡) = ((,)‘⟨𝑣, 𝑢⟩))
51		df-ov 7434	. . . . . . . . . . 11 ⊢ (𝑣(,)𝑢) = ((,)‘⟨𝑣, 𝑢⟩)
52	50, 51	eqtr4di 2795	. . . . . . . . . 10 ⊢ (𝑡 = ⟨𝑣, 𝑢⟩ → ((,)‘𝑡) = (𝑣(,)𝑢))
53	52	ineq2d 4220	. . . . . . . . 9 ⊢ (𝑡 = ⟨𝑣, 𝑢⟩ → ((𝑧(,)𝑤) ∩ ((,)‘𝑡)) = ((𝑧(,)𝑤) ∩ (𝑣(,)𝑢)))
54	53	eleq1d 2826	. . . . . . . 8 ⊢ (𝑡 = ⟨𝑣, 𝑢⟩ → (((𝑧(,)𝑤) ∩ ((,)‘𝑡)) ∈ ((,) “ (𝑆 × 𝑆)) ↔ ((𝑧(,)𝑤) ∩ (𝑣(,)𝑢)) ∈ ((,) “ (𝑆 × 𝑆))))
55	54	ralxp 5852	. . . . . . 7 ⊢ (∀𝑡 ∈ (𝑆 × 𝑆)((𝑧(,)𝑤) ∩ ((,)‘𝑡)) ∈ ((,) “ (𝑆 × 𝑆)) ↔ ∀𝑣 ∈ 𝑆 ∀𝑢 ∈ 𝑆 ((𝑧(,)𝑤) ∩ (𝑣(,)𝑢)) ∈ ((,) “ (𝑆 × 𝑆)))
56	49, 55	bitri 275	. . . . . 6 ⊢ (∀𝑦 ∈ ((,) “ (𝑆 × 𝑆))((𝑧(,)𝑤) ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆)) ↔ ∀𝑣 ∈ 𝑆 ∀𝑢 ∈ 𝑆 ((𝑧(,)𝑤) ∩ (𝑣(,)𝑢)) ∈ ((,) “ (𝑆 × 𝑆)))
57	45, 56	bitrdi 287	. . . . 5 ⊢ (𝑡 = ⟨𝑧, 𝑤⟩ → (∀𝑦 ∈ ((,) “ (𝑆 × 𝑆))(((,)‘𝑡) ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆)) ↔ ∀𝑣 ∈ 𝑆 ∀𝑢 ∈ 𝑆 ((𝑧(,)𝑤) ∩ (𝑣(,)𝑢)) ∈ ((,) “ (𝑆 × 𝑆))))
58	57	ralxp 5852	. . . 4 ⊢ (∀𝑡 ∈ (𝑆 × 𝑆)∀𝑦 ∈ ((,) “ (𝑆 × 𝑆))(((,)‘𝑡) ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆)) ↔ ∀𝑧 ∈ 𝑆 ∀𝑤 ∈ 𝑆 ∀𝑣 ∈ 𝑆 ∀𝑢 ∈ 𝑆 ((𝑧(,)𝑤) ∩ (𝑣(,)𝑢)) ∈ ((,) “ (𝑆 × 𝑆)))
59	39, 58	bitri 275	. . 3 ⊢ (∀𝑥 ∈ ((,) “ (𝑆 × 𝑆))∀𝑦 ∈ ((,) “ (𝑆 × 𝑆))(𝑥 ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆)) ↔ ∀𝑧 ∈ 𝑆 ∀𝑤 ∈ 𝑆 ∀𝑣 ∈ 𝑆 ∀𝑢 ∈ 𝑆 ((𝑧(,)𝑤) ∩ (𝑣(,)𝑢)) ∈ ((,) “ (𝑆 × 𝑆)))
60	32, 59	mpbir 231	. 2 ⊢ ∀𝑥 ∈ ((,) “ (𝑆 × 𝑆))∀𝑦 ∈ ((,) “ (𝑆 × 𝑆))(𝑥 ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆))
61		fiinbas 22959	. 2 ⊢ ((((,) “ (𝑆 × 𝑆)) ∈ V ∧ ∀𝑥 ∈ ((,) “ (𝑆 × 𝑆))∀𝑦 ∈ ((,) “ (𝑆 × 𝑆))(𝑥 ∩ 𝑦) ∈ ((,) “ (𝑆 × 𝑆))) → ((,) “ (𝑆 × 𝑆)) ∈ TopBases)
62	2, 60, 61	mp2an 692	1 ⊢ ((,) “ (𝑆 × 𝑆)) ∈ TopBases

Colors of variables: wff setvar class

Syntax hints: → wi 4 ↔ wb 206 ∧ wa 395 = wceq 1540 ∈ wcel 2108 ∀wral 3061 Vcvv 3480 ∩ cin 3950 ⊆ wss 3951 ifcif 4525 𝒫 cpw 4600 ⟨cop 4632 class class class wbr 5143 × cxp 5683 dom cdm 5685 “ cima 5688 Fun wfun 6555 Fn wfn 6556 ⟶wf 6557 ‘cfv 6561 (class class class)co 7431 ℝcr 11154 ℝ^*cxr 11294 ≤ cle 11296 (,)cioo 13387 TopBasesctb 22952

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 1910 ax-6 1967 ax-7 2007 ax-8 2110 ax-9 2118 ax-10 2141 ax-11 2157 ax-12 2177 ax-ext 2708 ax-sep 5296 ax-nul 5306 ax-pow 5365 ax-pr 5432 ax-un 7755 ax-cnex 11211 ax-resscn 11212 ax-pre-lttri 11229 ax-pre-lttrn 11230

This theorem depends on definitions: df-bi 207 df-an 396 df-or 849 df-3or 1088 df-3an 1089 df-tru 1543 df-fal 1553 df-ex 1780 df-nf 1784 df-sb 2065 df-mo 2540 df-eu 2569 df-clab 2715 df-cleq 2729 df-clel 2816 df-nfc 2892 df-ne 2941 df-nel 3047 df-ral 3062 df-rex 3071 df-rab 3437 df-v 3482 df-sbc 3789 df-csb 3900 df-dif 3954 df-un 3956 df-in 3958 df-ss 3968 df-nul 4334 df-if 4526 df-pw 4602 df-sn 4627 df-pr 4629 df-op 4633 df-uni 4908 df-iun 4993 df-br 5144 df-opab 5206 df-mpt 5226 df-id 5578 df-po 5592 df-so 5593 df-xp 5691 df-rel 5692 df-cnv 5693 df-co 5694 df-dm 5695 df-rn 5696 df-res 5697 df-ima 5698 df-iota 6514 df-fun 6563 df-fn 6564 df-f 6565 df-f1 6566 df-fo 6567 df-f1o 6568 df-fv 6569 df-ov 7434 df-oprab 7435 df-mpo 7436 df-1st 8014 df-2nd 8015 df-er 8745 df-en 8986 df-dom 8987 df-sdom 8988 df-pnf 11297 df-mnf 11298 df-xr 11299 df-ltxr 11300 df-le 11301 df-ioo 13391 df-bases 22953

This theorem is referenced by: qtopbas 24780 retopbas 24781

W3C validator