Metamath Proof Explorer


Theorem fourierdlem33

Description: Limit of a continuous function on an open subinterval. Upper bound version. (Contributed by Glauco Siliprandi, 11-Dec-2019)

Ref Expression
Hypotheses fourierdlem33.1 ⊢ φ → A ∈ ℝ
fourierdlem33.2 ⊢ φ → B ∈ ℝ
fourierdlem33.3 ⊢ φ → A < B
fourierdlem33.4 ⊢ φ → F : A B ⟶cn ℂ
fourierdlem33.5 ⊢ φ → L ∈ F lim ℂ B
fourierdlem33.6 ⊢ φ → C ∈ ℝ
fourierdlem33.7 ⊢ φ → D ∈ ℝ
fourierdlem33.8 ⊢ φ → C < D
fourierdlem33.ss ⊢ φ → C D ⊆ A B
fourierdlem33.y ⊢ Y = if D = B L F ⁡ D
fourierdlem33.10 ⊢ J = TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∪ B
Assertion fourierdlem33 ⊢ φ → Y ∈ F ↾ C D lim ℂ D

Proof

Step Hyp Ref Expression
1 fourierdlem33.1 ⊢ φ → A ∈ ℝ
2 fourierdlem33.2 ⊢ φ → B ∈ ℝ
3 fourierdlem33.3 ⊢ φ → A < B
4 fourierdlem33.4 ⊢ φ → F : A B ⟶cn ℂ
5 fourierdlem33.5 ⊢ φ → L ∈ F lim ℂ B
6 fourierdlem33.6 ⊢ φ → C ∈ ℝ
7 fourierdlem33.7 ⊢ φ → D ∈ ℝ
8 fourierdlem33.8 ⊢ φ → C < D
9 fourierdlem33.ss ⊢ φ → C D ⊆ A B
10 fourierdlem33.y ⊢ Y = if D = B L F ⁡ D
11 fourierdlem33.10 ⊢ J = TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∪ B
12 5 adantr ⊢ φ ∧ D = B → L ∈ F lim ℂ B
13 iftrue ⊢ D = B → if D = B L F ⁡ D = L
14 10 13 eqtr2id ⊢ D = B → L = Y
15 14 adantl ⊢ φ ∧ D = B → L = Y
16 oveq2 ⊢ D = B → F ↾ C D lim ℂ D = F ↾ C D lim ℂ B
17 16 adantl ⊢ φ ∧ D = B → F ↾ C D lim ℂ D = F ↾ C D lim ℂ B
18 cncff ⊢ F : A B ⟶cn ℂ → F : A B ⟶ ℂ
19 4 18 syl ⊢ φ → F : A B ⟶ ℂ
20 19 adantr ⊢ φ ∧ D = B → F : A B ⟶ ℂ
21 9 adantr ⊢ φ ∧ D = B → C D ⊆ A B
22 ioosscn ⊢ A B ⊆ ℂ
23 22 a1i ⊢ φ ∧ D = B → A B ⊆ ℂ
24 eqid ⊢ TopOpen ⁡ ℂ fld = TopOpen ⁡ ℂ fld
25 7 leidd ⊢ φ → D ≤ D
26 6 rexrd ⊢ φ → C ∈ ℝ *
27 elioc2 ⊢ C ∈ ℝ * ∧ D ∈ ℝ → D ∈ C D ↔ D ∈ ℝ ∧ C < D ∧ D ≤ D
28 26 7 27 syl2anc ⊢ φ → D ∈ C D ↔ D ∈ ℝ ∧ C < D ∧ D ≤ D
29 7 8 25 28 mpbir3and ⊢ φ → D ∈ C D
30 29 adantr ⊢ φ ∧ D = B → D ∈ C D
31 eqcom ⊢ D = B ↔ B = D
32 31 bilani ⊢ φ ∧ D = B → B = D
33 24 cnfldtop ⊢ TopOpen ⁡ ℂ fld ∈ Top
34 1 rexrd ⊢ φ → A ∈ ℝ *
35 2 rexrd ⊢ φ → B ∈ ℝ *
36 ioounsn ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ A < B → A B ∪ B = A B
37 34 35 3 36 syl3anc ⊢ φ → A B ∪ B = A B
38 ovex ⊢ A B ∈ V
39 38 a1i ⊢ φ → A B ∈ V
40 37 39 eqeltrd ⊢ φ → A B ∪ B ∈ V
41 resttop ⊢ TopOpen ⁡ ℂ fld ∈ Top ∧ A B ∪ B ∈ V → TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∪ B ∈ Top
42 33 40 41 sylancr ⊢ φ → TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∪ B ∈ Top
43 11 42 eqeltrid ⊢ φ → J ∈ Top
44 43 adantr ⊢ φ ∧ D = B → J ∈ Top
45 oveq2 ⊢ D = B → C D = C B
46 45 adantl ⊢ φ ∧ D = B → C D = C B
47 26 adantr ⊢ φ ∧ x ∈ C B → C ∈ ℝ *
48 pnfxr ⊢ +∞ ∈ ℝ *
49 48 a1i ⊢ φ ∧ x ∈ C B → +∞ ∈ ℝ *
50 simpr ⊢ φ ∧ x ∈ C B → x ∈ C B
51 2 adantr ⊢ φ ∧ x ∈ C B → B ∈ ℝ
52 elioc2 ⊢ C ∈ ℝ * ∧ B ∈ ℝ → x ∈ C B ↔ x ∈ ℝ ∧ C < x ∧ x ≤ B
53 47 51 52 syl2anc ⊢ φ ∧ x ∈ C B → x ∈ C B ↔ x ∈ ℝ ∧ C < x ∧ x ≤ B
54 50 53 mpbid ⊢ φ ∧ x ∈ C B → x ∈ ℝ ∧ C < x ∧ x ≤ B
55 54 simp1d ⊢ φ ∧ x ∈ C B → x ∈ ℝ
56 54 simp2d ⊢ φ ∧ x ∈ C B → C < x
57 55 ltpnfd ⊢ φ ∧ x ∈ C B → x < +∞
58 47 49 55 56 57 eliood ⊢ φ ∧ x ∈ C B → x ∈ C +∞
59 1 adantr ⊢ φ ∧ x ∈ C B → A ∈ ℝ
60 6 adantr ⊢ φ ∧ x ∈ C B → C ∈ ℝ
61 1 2 6 7 8 9 fourierdlem10 ⊢ φ → A ≤ C ∧ D ≤ B
62 61 simpld ⊢ φ → A ≤ C
63 62 adantr ⊢ φ ∧ x ∈ C B → A ≤ C
64 59 60 55 63 56 lelttrd ⊢ φ ∧ x ∈ C B → A < x
65 54 simp3d ⊢ φ ∧ x ∈ C B → x ≤ B
66 34 adantr ⊢ φ ∧ x ∈ C B → A ∈ ℝ *
67 elioc2 ⊢ A ∈ ℝ * ∧ B ∈ ℝ → x ∈ A B ↔ x ∈ ℝ ∧ A < x ∧ x ≤ B
68 66 51 67 syl2anc ⊢ φ ∧ x ∈ C B → x ∈ A B ↔ x ∈ ℝ ∧ A < x ∧ x ≤ B
69 55 64 65 68 mpbir3and ⊢ φ ∧ x ∈ C B → x ∈ A B
70 58 69 elind ⊢ φ ∧ x ∈ C B → x ∈ C +∞ ∩ A B
71 elinel1 ⊢ x ∈ C +∞ ∩ A B → x ∈ C +∞
72 elioore ⊢ x ∈ C +∞ → x ∈ ℝ
73 71 72 syl ⊢ x ∈ C +∞ ∩ A B → x ∈ ℝ
74 73 adantl ⊢ φ ∧ x ∈ C +∞ ∩ A B → x ∈ ℝ
75 26 adantr ⊢ φ ∧ x ∈ C +∞ ∩ A B → C ∈ ℝ *
76 48 a1i ⊢ φ ∧ x ∈ C +∞ ∩ A B → +∞ ∈ ℝ *
77 71 adantl ⊢ φ ∧ x ∈ C +∞ ∩ A B → x ∈ C +∞
78 ioogtlb ⊢ C ∈ ℝ * ∧ +∞ ∈ ℝ * ∧ x ∈ C +∞ → C < x
79 75 76 77 78 syl3anc ⊢ φ ∧ x ∈ C +∞ ∩ A B → C < x
80 elinel2 ⊢ x ∈ C +∞ ∩ A B → x ∈ A B
81 80 adantl ⊢ φ ∧ x ∈ C +∞ ∩ A B → x ∈ A B
82 34 adantr ⊢ φ ∧ x ∈ C +∞ ∩ A B → A ∈ ℝ *
83 2 adantr ⊢ φ ∧ x ∈ C +∞ ∩ A B → B ∈ ℝ
84 82 83 67 syl2anc ⊢ φ ∧ x ∈ C +∞ ∩ A B → x ∈ A B ↔ x ∈ ℝ ∧ A < x ∧ x ≤ B
85 81 84 mpbid ⊢ φ ∧ x ∈ C +∞ ∩ A B → x ∈ ℝ ∧ A < x ∧ x ≤ B
86 85 simp3d ⊢ φ ∧ x ∈ C +∞ ∩ A B → x ≤ B
87 75 83 52 syl2anc ⊢ φ ∧ x ∈ C +∞ ∩ A B → x ∈ C B ↔ x ∈ ℝ ∧ C < x ∧ x ≤ B
88 74 79 86 87 mpbir3and ⊢ φ ∧ x ∈ C +∞ ∩ A B → x ∈ C B
89 70 88 impbida ⊢ φ → x ∈ C B ↔ x ∈ C +∞ ∩ A B
90 89 eqrdv ⊢ φ → C B = C +∞ ∩ A B
91 retop ⊢ topGen ⁡ ran ⁡ . ∈ Top
92 91 a1i ⊢ φ → topGen ⁡ ran ⁡ . ∈ Top
93 iooretop ⊢ C +∞ ∈ topGen ⁡ ran ⁡ .
94 93 a1i ⊢ φ → C +∞ ∈ topGen ⁡ ran ⁡ .
95 elrestr ⊢ topGen ⁡ ran ⁡ . ∈ Top ∧ A B ∈ V ∧ C +∞ ∈ topGen ⁡ ran ⁡ . → C +∞ ∩ A B ∈ topGen ⁡ ran ⁡ . ↾ 𝑡 A B
96 92 39 94 95 syl3anc ⊢ φ → C +∞ ∩ A B ∈ topGen ⁡ ran ⁡ . ↾ 𝑡 A B
97 90 96 eqeltrd ⊢ φ → C B ∈ topGen ⁡ ran ⁡ . ↾ 𝑡 A B
98 97 adantr ⊢ φ ∧ D = B → C B ∈ topGen ⁡ ran ⁡ . ↾ 𝑡 A B
99 46 98 eqeltrd ⊢ φ ∧ D = B → C D ∈ topGen ⁡ ran ⁡ . ↾ 𝑡 A B
100 11 a1i ⊢ φ → J = TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∪ B
101 37 oveq2d ⊢ φ → TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∪ B = TopOpen ⁡ ℂ fld ↾ 𝑡 A B
102 33 a1i ⊢ φ → TopOpen ⁡ ℂ fld ∈ Top
103 iocssre ⊢ A ∈ ℝ * ∧ B ∈ ℝ → A B ⊆ ℝ
104 34 2 103 syl2anc ⊢ φ → A B ⊆ ℝ
105 reex ⊢ ℝ ∈ V
106 105 a1i ⊢ φ → ℝ ∈ V
107 restabs ⊢ TopOpen ⁡ ℂ fld ∈ Top ∧ A B ⊆ ℝ ∧ ℝ ∈ V → TopOpen ⁡ ℂ fld ↾ 𝑡 ℝ ↾ 𝑡 A B = TopOpen ⁡ ℂ fld ↾ 𝑡 A B
108 102 104 106 107 syl3anc ⊢ φ → TopOpen ⁡ ℂ fld ↾ 𝑡 ℝ ↾ 𝑡 A B = TopOpen ⁡ ℂ fld ↾ 𝑡 A B
109 tgioo4 ⊢ topGen ⁡ ran ⁡ . = TopOpen ⁡ ℂ fld ↾ 𝑡 ℝ
110 109 eqcomi ⊢ TopOpen ⁡ ℂ fld ↾ 𝑡 ℝ = topGen ⁡ ran ⁡ .
111 110 oveq1i ⊢ TopOpen ⁡ ℂ fld ↾ 𝑡 ℝ ↾ 𝑡 A B = topGen ⁡ ran ⁡ . ↾ 𝑡 A B
112 108 111 eqtr3di ⊢ φ → TopOpen ⁡ ℂ fld ↾ 𝑡 A B = topGen ⁡ ran ⁡ . ↾ 𝑡 A B
113 100 101 112 3eqtrrd ⊢ φ → topGen ⁡ ran ⁡ . ↾ 𝑡 A B = J
114 113 adantr ⊢ φ ∧ D = B → topGen ⁡ ran ⁡ . ↾ 𝑡 A B = J
115 99 114 eleqtrd ⊢ φ ∧ D = B → C D ∈ J
116 isopn3i ⊢ J ∈ Top ∧ C D ∈ J → int ⁡ J ⁡ C D = C D
117 44 115 116 syl2anc ⊢ φ ∧ D = B → int ⁡ J ⁡ C D = C D
118 30 32 117 3eltr4d ⊢ φ ∧ D = B → B ∈ int ⁡ J ⁡ C D
119 sneq ⊢ D = B → D = B
120 119 eqcomd ⊢ D = B → B = D
121 120 uneq2d ⊢ D = B → C D ∪ B = C D ∪ D
122 121 adantl ⊢ φ ∧ D = B → C D ∪ B = C D ∪ D
123 7 rexrd ⊢ φ → D ∈ ℝ *
124 ioounsn ⊢ C ∈ ℝ * ∧ D ∈ ℝ * ∧ C < D → C D ∪ D = C D
125 26 123 8 124 syl3anc ⊢ φ → C D ∪ D = C D
126 125 adantr ⊢ φ ∧ D = B → C D ∪ D = C D
127 122 126 eqtr2d ⊢ φ ∧ D = B → C D = C D ∪ B
128 127 fveq2d ⊢ φ ∧ D = B → int ⁡ J ⁡ C D = int ⁡ J ⁡ C D ∪ B
129 118 128 eleqtrd ⊢ φ ∧ D = B → B ∈ int ⁡ J ⁡ C D ∪ B
130 20 21 23 24 11 129 limcres ⊢ φ ∧ D = B → F ↾ C D lim ℂ B = F lim ℂ B
131 17 130 eqtr2d ⊢ φ ∧ D = B → F lim ℂ B = F ↾ C D lim ℂ D
132 12 15 131 3eltr3d ⊢ φ ∧ D = B → Y ∈ F ↾ C D lim ℂ D
133 limcresi ⊢ F lim ℂ D ⊆ F ↾ C D lim ℂ D
134 iffalse ⊢ ¬ D = B → if D = B L F ⁡ D = F ⁡ D
135 10 134 eqtrid ⊢ ¬ D = B → Y = F ⁡ D
136 135 adantl ⊢ φ ∧ ¬ D = B → Y = F ⁡ D
137 ssid ⊢ ℂ ⊆ ℂ
138 137 a1i ⊢ φ → ℂ ⊆ ℂ
139 eqid ⊢ TopOpen ⁡ ℂ fld ↾ 𝑡 A B = TopOpen ⁡ ℂ fld ↾ 𝑡 A B
140 unicntop ⊢ ℂ = ⋃ TopOpen ⁡ ℂ fld
141 140 restid ⊢ TopOpen ⁡ ℂ fld ∈ Top → TopOpen ⁡ ℂ fld ↾ 𝑡 ℂ = TopOpen ⁡ ℂ fld
142 33 141 ax-mp ⊢ TopOpen ⁡ ℂ fld ↾ 𝑡 ℂ = TopOpen ⁡ ℂ fld
143 142 eqcomi ⊢ TopOpen ⁡ ℂ fld = TopOpen ⁡ ℂ fld ↾ 𝑡 ℂ
144 24 139 143 cncfcn ⊢ A B ⊆ ℂ ∧ ℂ ⊆ ℂ → A B ⟶cn ℂ = TopOpen ⁡ ℂ fld ↾ 𝑡 A B Cn TopOpen ⁡ ℂ fld
145 22 138 144 sylancr ⊢ φ → A B ⟶cn ℂ = TopOpen ⁡ ℂ fld ↾ 𝑡 A B Cn TopOpen ⁡ ℂ fld
146 4 145 eleqtrd ⊢ φ → F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B Cn TopOpen ⁡ ℂ fld
147 24 cnfldtopon ⊢ TopOpen ⁡ ℂ fld ∈ TopOn ⁡ ℂ
148 22 a1i ⊢ φ → A B ⊆ ℂ
149 resttopon ⊢ TopOpen ⁡ ℂ fld ∈ TopOn ⁡ ℂ ∧ A B ⊆ ℂ → TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∈ TopOn ⁡ A B
150 147 148 149 sylancr ⊢ φ → TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∈ TopOn ⁡ A B
151 147 a1i ⊢ φ → TopOpen ⁡ ℂ fld ∈ TopOn ⁡ ℂ
152 cncnp ⊢ TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∈ TopOn ⁡ A B ∧ TopOpen ⁡ ℂ fld ∈ TopOn ⁡ ℂ → F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B Cn TopOpen ⁡ ℂ fld ↔ F : A B ⟶ ℂ ∧ ∀ x ∈ A B F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ x
153 150 151 152 syl2anc ⊢ φ → F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B Cn TopOpen ⁡ ℂ fld ↔ F : A B ⟶ ℂ ∧ ∀ x ∈ A B F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ x
154 146 153 mpbid ⊢ φ → F : A B ⟶ ℂ ∧ ∀ x ∈ A B F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ x
155 154 simprd ⊢ φ → ∀ x ∈ A B F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ x
156 155 adantr ⊢ φ ∧ ¬ D = B → ∀ x ∈ A B F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ x
157 34 adantr ⊢ φ ∧ ¬ D = B → A ∈ ℝ *
158 35 adantr ⊢ φ ∧ ¬ D = B → B ∈ ℝ *
159 7 adantr ⊢ φ ∧ ¬ D = B → D ∈ ℝ
160 1 6 7 62 8 lelttrd ⊢ φ → A < D
161 160 adantr ⊢ φ ∧ ¬ D = B → A < D
162 2 adantr ⊢ φ ∧ ¬ D = B → B ∈ ℝ
163 61 simprd ⊢ φ → D ≤ B
164 163 adantr ⊢ φ ∧ ¬ D = B → D ≤ B
165 neqne ⊢ ¬ D = B → D ≠ B
166 165 necomd ⊢ ¬ D = B → B ≠ D
167 166 adantl ⊢ φ ∧ ¬ D = B → B ≠ D
168 159 162 164 167 leneltd ⊢ φ ∧ ¬ D = B → D < B
169 157 158 159 161 168 eliood ⊢ φ ∧ ¬ D = B → D ∈ A B
170 fveq2 ⊢ x = D → TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ x = TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ D
171 170 eleq2d ⊢ x = D → F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ x ↔ F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ D
172 171 rspccva ⊢ ∀ x ∈ A B F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ x ∧ D ∈ A B → F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ D
173 156 169 172 syl2anc ⊢ φ ∧ ¬ D = B → F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ D
174 24 139 cnplimc ⊢ A B ⊆ ℂ ∧ D ∈ A B → F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ D ↔ F : A B ⟶ ℂ ∧ F ⁡ D ∈ F lim ℂ D
175 22 169 174 sylancr ⊢ φ ∧ ¬ D = B → F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ D ↔ F : A B ⟶ ℂ ∧ F ⁡ D ∈ F lim ℂ D
176 173 175 mpbid ⊢ φ ∧ ¬ D = B → F : A B ⟶ ℂ ∧ F ⁡ D ∈ F lim ℂ D
177 176 simprd ⊢ φ ∧ ¬ D = B → F ⁡ D ∈ F lim ℂ D
178 136 177 eqeltrd ⊢ φ ∧ ¬ D = B → Y ∈ F lim ℂ D
179 133 178 sselid ⊢ φ ∧ ¬ D = B → Y ∈ F ↾ C D lim ℂ D
180 132 179 pm2.61dan ⊢ φ → Y ∈ F ↾ C D lim ℂ D