Metamath Proof Explorer


Theorem icoopn

Description: A left-closed right-open interval is an open set of the standard topology restricted to an interval that contains the original interval and has the same lower bound. (Contributed by Glauco Siliprandi, 11-Dec-2019)

Ref Expression
Hypotheses icoopn.a ⊢ φ → A ∈ ℝ
icoopn.c ⊢ φ → C ∈ ℝ *
icoopn.b ⊢ φ → B ∈ ℝ *
icoopn.k ⊢ K = topGen ⁡ ran ⁡ .
icoopn.j ⊢ J = K ↾ 𝑡 A B
icoopn.cleb ⊢ φ → C ≤ B
Assertion icoopn ⊢ φ → A C ∈ J

Proof

Step Hyp Ref Expression
1 icoopn.a ⊢ φ → A ∈ ℝ
2 icoopn.c ⊢ φ → C ∈ ℝ *
3 icoopn.b ⊢ φ → B ∈ ℝ *
4 icoopn.k ⊢ K = topGen ⁡ ran ⁡ .
5 icoopn.j ⊢ J = K ↾ 𝑡 A B
6 icoopn.cleb ⊢ φ → C ≤ B
7 retop ⊢ topGen ⁡ ran ⁡ . ∈ Top
8 4 7 eqeltri ⊢ K ∈ Top
9 8 a1i ⊢ φ → K ∈ Top
10 ovexd ⊢ φ → A B ∈ V
11 iooretop ⊢ −∞ C ∈ topGen ⁡ ran ⁡ .
12 11 4 eleqtrri ⊢ −∞ C ∈ K
13 12 a1i ⊢ φ → −∞ C ∈ K
14 elrestr ⊢ K ∈ Top ∧ A B ∈ V ∧ −∞ C ∈ K → −∞ C ∩ A B ∈ K ↾ 𝑡 A B
15 9 10 13 14 syl3anc ⊢ φ → −∞ C ∩ A B ∈ K ↾ 𝑡 A B
16 1 rexrd ⊢ φ → A ∈ ℝ *
17 16 adantr ⊢ φ ∧ x ∈ −∞ C ∩ A B → A ∈ ℝ *
18 2 adantr ⊢ φ ∧ x ∈ −∞ C ∩ A B → C ∈ ℝ *
19 elinel1 ⊢ x ∈ −∞ C ∩ A B → x ∈ −∞ C
20 elioore ⊢ x ∈ −∞ C → x ∈ ℝ
21 19 20 syl ⊢ x ∈ −∞ C ∩ A B → x ∈ ℝ
22 21 rexrd ⊢ x ∈ −∞ C ∩ A B → x ∈ ℝ *
23 22 adantl ⊢ φ ∧ x ∈ −∞ C ∩ A B → x ∈ ℝ *
24 3 adantr ⊢ φ ∧ x ∈ −∞ C ∩ A B → B ∈ ℝ *
25 elinel2 ⊢ x ∈ −∞ C ∩ A B → x ∈ A B
26 25 adantl ⊢ φ ∧ x ∈ −∞ C ∩ A B → x ∈ A B
27 icogelb ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ x ∈ A B → A ≤ x
28 17 24 26 27 syl3anc ⊢ φ ∧ x ∈ −∞ C ∩ A B → A ≤ x
29 mnfxr ⊢ −∞ ∈ ℝ *
30 29 a1i ⊢ φ ∧ x ∈ −∞ C ∩ A B → −∞ ∈ ℝ *
31 19 adantl ⊢ φ ∧ x ∈ −∞ C ∩ A B → x ∈ −∞ C
32 iooltub ⊢ −∞ ∈ ℝ * ∧ C ∈ ℝ * ∧ x ∈ −∞ C → x < C
33 30 18 31 32 syl3anc ⊢ φ ∧ x ∈ −∞ C ∩ A B → x < C
34 17 18 23 28 33 elicod ⊢ φ ∧ x ∈ −∞ C ∩ A B → x ∈ A C
35 29 a1i ⊢ φ ∧ x ∈ A C → −∞ ∈ ℝ *
36 2 adantr ⊢ φ ∧ x ∈ A C → C ∈ ℝ *
37 icossre ⊢ A ∈ ℝ ∧ C ∈ ℝ * → A C ⊆ ℝ
38 1 2 37 syl2anc ⊢ φ → A C ⊆ ℝ
39 38 sselda ⊢ φ ∧ x ∈ A C → x ∈ ℝ
40 39 mnfltd ⊢ φ ∧ x ∈ A C → −∞ < x
41 16 adantr ⊢ φ ∧ x ∈ A C → A ∈ ℝ *
42 simpr ⊢ φ ∧ x ∈ A C → x ∈ A C
43 icoltub ⊢ A ∈ ℝ * ∧ C ∈ ℝ * ∧ x ∈ A C → x < C
44 41 36 42 43 syl3anc ⊢ φ ∧ x ∈ A C → x < C
45 35 36 39 40 44 eliood ⊢ φ ∧ x ∈ A C → x ∈ −∞ C
46 3 adantr ⊢ φ ∧ x ∈ A C → B ∈ ℝ *
47 39 rexrd ⊢ φ ∧ x ∈ A C → x ∈ ℝ *
48 icogelb ⊢ A ∈ ℝ * ∧ C ∈ ℝ * ∧ x ∈ A C → A ≤ x
49 41 36 42 48 syl3anc ⊢ φ ∧ x ∈ A C → A ≤ x
50 6 adantr ⊢ φ ∧ x ∈ A C → C ≤ B
51 47 36 46 44 50 xrltletrd ⊢ φ ∧ x ∈ A C → x < B
52 41 46 47 49 51 elicod ⊢ φ ∧ x ∈ A C → x ∈ A B
53 45 52 elind ⊢ φ ∧ x ∈ A C → x ∈ −∞ C ∩ A B
54 34 53 impbida ⊢ φ → x ∈ −∞ C ∩ A B ↔ x ∈ A C
55 54 eqrdv ⊢ φ → −∞ C ∩ A B = A C
56 5 eqcomi ⊢ K ↾ 𝑡 A B = J
57 56 a1i ⊢ φ → K ↾ 𝑡 A B = J
58 15 55 57 3eltr3d ⊢ φ → A C ∈ J