Metamath Proof Explorer


Theorem fourierdlem32

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

Ref Expression
Hypotheses fourierdlem32.a ⊢ φ → A ∈ ℝ
fourierdlem32.b ⊢ φ → B ∈ ℝ
fourierdlem32.altb ⊢ φ → A < B
fourierdlem32.f ⊢ φ → F : A B ⟶cn ℂ
fourierdlem32.l ⊢ φ → R ∈ F lim ℂ A
fourierdlem32.c ⊢ φ → C ∈ ℝ
fourierdlem32.d ⊢ φ → D ∈ ℝ
fourierdlem32.cltd ⊢ φ → C < D
fourierdlem32.ss ⊢ φ → C D ⊆ A B
fourierdlem32.y ⊢ Y = if C = A R F ⁡ C
fourierdlem32.j ⊢ J = TopOpen ⁡ ℂ fld ↾ 𝑡 A B
Assertion fourierdlem32 ⊢ φ → Y ∈ F ↾ C D lim ℂ C

Proof

Step Hyp Ref Expression
1 fourierdlem32.a ⊢ φ → A ∈ ℝ
2 fourierdlem32.b ⊢ φ → B ∈ ℝ
3 fourierdlem32.altb ⊢ φ → A < B
4 fourierdlem32.f ⊢ φ → F : A B ⟶cn ℂ
5 fourierdlem32.l ⊢ φ → R ∈ F lim ℂ A
6 fourierdlem32.c ⊢ φ → C ∈ ℝ
7 fourierdlem32.d ⊢ φ → D ∈ ℝ
8 fourierdlem32.cltd ⊢ φ → C < D
9 fourierdlem32.ss ⊢ φ → C D ⊆ A B
10 fourierdlem32.y ⊢ Y = if C = A R F ⁡ C
11 fourierdlem32.j ⊢ J = TopOpen ⁡ ℂ fld ↾ 𝑡 A B
12 5 adantr ⊢ φ ∧ C = A → R ∈ F lim ℂ A
13 iftrue ⊢ C = A → if C = A R F ⁡ C = R
14 10 13 eqtr2id ⊢ C = A → R = Y
15 14 adantl ⊢ φ ∧ C = A → R = Y
16 oveq2 ⊢ C = A → F ↾ C D lim ℂ C = F ↾ C D lim ℂ A
17 16 adantl ⊢ φ ∧ C = A → F ↾ C D lim ℂ C = F ↾ C D lim ℂ A
18 cncff ⊢ F : A B ⟶cn ℂ → F : A B ⟶ ℂ
19 4 18 syl ⊢ φ → F : A B ⟶ ℂ
20 19 adantr ⊢ φ ∧ C = A → F : A B ⟶ ℂ
21 9 adantr ⊢ φ ∧ C = A → C D ⊆ A B
22 ioosscn ⊢ A B ⊆ ℂ
23 22 a1i ⊢ φ ∧ C = A → A B ⊆ ℂ
24 eqid ⊢ TopOpen ⁡ ℂ fld = TopOpen ⁡ ℂ fld
25 eqid ⊢ TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∪ A = TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∪ A
26 6 leidd ⊢ φ → C ≤ C
27 7 rexrd ⊢ φ → D ∈ ℝ *
28 elico2 ⊢ C ∈ ℝ ∧ D ∈ ℝ * → C ∈ C D ↔ C ∈ ℝ ∧ C ≤ C ∧ C < D
29 6 27 28 syl2anc ⊢ φ → C ∈ C D ↔ C ∈ ℝ ∧ C ≤ C ∧ C < D
30 6 26 8 29 mpbir3and ⊢ φ → C ∈ C D
31 30 adantr ⊢ φ ∧ C = A → C ∈ C D
32 24 cnfldtop ⊢ TopOpen ⁡ ℂ fld ∈ Top
33 ovex ⊢ A B ∈ V
34 33 a1i ⊢ φ ∧ C = A → A B ∈ V
35 resttop ⊢ TopOpen ⁡ ℂ fld ∈ Top ∧ A B ∈ V → TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∈ Top
36 32 34 35 sylancr ⊢ φ ∧ C = A → TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∈ Top
37 11 36 eqeltrid ⊢ φ ∧ C = A → J ∈ Top
38 mnfxr ⊢ −∞ ∈ ℝ *
39 38 a1i ⊢ φ ∧ x ∈ A D → −∞ ∈ ℝ *
40 27 adantr ⊢ φ ∧ x ∈ A D → D ∈ ℝ *
41 simpr ⊢ φ ∧ x ∈ A D → x ∈ A D
42 1 adantr ⊢ φ ∧ x ∈ A D → A ∈ ℝ
43 elico2 ⊢ A ∈ ℝ ∧ D ∈ ℝ * → x ∈ A D ↔ x ∈ ℝ ∧ A ≤ x ∧ x < D
44 42 40 43 syl2anc ⊢ φ ∧ x ∈ A D → x ∈ A D ↔ x ∈ ℝ ∧ A ≤ x ∧ x < D
45 41 44 mpbid ⊢ φ ∧ x ∈ A D → x ∈ ℝ ∧ A ≤ x ∧ x < D
46 45 simp1d ⊢ φ ∧ x ∈ A D → x ∈ ℝ
47 46 mnfltd ⊢ φ ∧ x ∈ A D → −∞ < x
48 45 simp3d ⊢ φ ∧ x ∈ A D → x < D
49 39 40 46 47 48 eliood ⊢ φ ∧ x ∈ A D → x ∈ −∞ D
50 45 simp2d ⊢ φ ∧ x ∈ A D → A ≤ x
51 7 adantr ⊢ φ ∧ x ∈ A D → D ∈ ℝ
52 2 adantr ⊢ φ ∧ x ∈ A D → B ∈ ℝ
53 1 2 6 7 8 9 fourierdlem10 ⊢ φ → A ≤ C ∧ D ≤ B
54 53 simprd ⊢ φ → D ≤ B
55 54 adantr ⊢ φ ∧ x ∈ A D → D ≤ B
56 46 51 52 48 55 ltletrd ⊢ φ ∧ x ∈ A D → x < B
57 2 rexrd ⊢ φ → B ∈ ℝ *
58 57 adantr ⊢ φ ∧ x ∈ A D → B ∈ ℝ *
59 elico2 ⊢ A ∈ ℝ ∧ B ∈ ℝ * → x ∈ A B ↔ x ∈ ℝ ∧ A ≤ x ∧ x < B
60 42 58 59 syl2anc ⊢ φ ∧ x ∈ A D → x ∈ A B ↔ x ∈ ℝ ∧ A ≤ x ∧ x < B
61 46 50 56 60 mpbir3and ⊢ φ ∧ x ∈ A D → x ∈ A B
62 49 61 elind ⊢ φ ∧ x ∈ A D → x ∈ −∞ D ∩ A B
63 elinel1 ⊢ x ∈ −∞ D ∩ A B → x ∈ −∞ D
64 elioore ⊢ x ∈ −∞ D → x ∈ ℝ
65 63 64 syl ⊢ x ∈ −∞ D ∩ A B → x ∈ ℝ
66 65 adantl ⊢ φ ∧ x ∈ −∞ D ∩ A B → x ∈ ℝ
67 elinel2 ⊢ x ∈ −∞ D ∩ A B → x ∈ A B
68 67 adantl ⊢ φ ∧ x ∈ −∞ D ∩ A B → x ∈ A B
69 1 adantr ⊢ φ ∧ x ∈ −∞ D ∩ A B → A ∈ ℝ
70 57 adantr ⊢ φ ∧ x ∈ −∞ D ∩ A B → B ∈ ℝ *
71 69 70 59 syl2anc ⊢ φ ∧ x ∈ −∞ D ∩ A B → x ∈ A B ↔ x ∈ ℝ ∧ A ≤ x ∧ x < B
72 68 71 mpbid ⊢ φ ∧ x ∈ −∞ D ∩ A B → x ∈ ℝ ∧ A ≤ x ∧ x < B
73 72 simp2d ⊢ φ ∧ x ∈ −∞ D ∩ A B → A ≤ x
74 63 adantl ⊢ φ ∧ x ∈ −∞ D ∩ A B → x ∈ −∞ D
75 27 adantr ⊢ φ ∧ x ∈ −∞ D ∩ A B → D ∈ ℝ *
76 elioo2 ⊢ −∞ ∈ ℝ * ∧ D ∈ ℝ * → x ∈ −∞ D ↔ x ∈ ℝ ∧ −∞ < x ∧ x < D
77 38 75 76 sylancr ⊢ φ ∧ x ∈ −∞ D ∩ A B → x ∈ −∞ D ↔ x ∈ ℝ ∧ −∞ < x ∧ x < D
78 74 77 mpbid ⊢ φ ∧ x ∈ −∞ D ∩ A B → x ∈ ℝ ∧ −∞ < x ∧ x < D
79 78 simp3d ⊢ φ ∧ x ∈ −∞ D ∩ A B → x < D
80 69 75 43 syl2anc ⊢ φ ∧ x ∈ −∞ D ∩ A B → x ∈ A D ↔ x ∈ ℝ ∧ A ≤ x ∧ x < D
81 66 73 79 80 mpbir3and ⊢ φ ∧ x ∈ −∞ D ∩ A B → x ∈ A D
82 62 81 impbida ⊢ φ → x ∈ A D ↔ x ∈ −∞ D ∩ A B
83 82 eqrdv ⊢ φ → A D = −∞ D ∩ A B
84 retop ⊢ topGen ⁡ ran ⁡ . ∈ Top
85 84 a1i ⊢ φ → topGen ⁡ ran ⁡ . ∈ Top
86 33 a1i ⊢ φ → A B ∈ V
87 iooretop ⊢ −∞ D ∈ topGen ⁡ ran ⁡ .
88 87 a1i ⊢ φ → −∞ D ∈ topGen ⁡ ran ⁡ .
89 elrestr ⊢ topGen ⁡ ran ⁡ . ∈ Top ∧ A B ∈ V ∧ −∞ D ∈ topGen ⁡ ran ⁡ . → −∞ D ∩ A B ∈ topGen ⁡ ran ⁡ . ↾ 𝑡 A B
90 85 86 88 89 syl3anc ⊢ φ → −∞ D ∩ A B ∈ topGen ⁡ ran ⁡ . ↾ 𝑡 A B
91 83 90 eqeltrd ⊢ φ → A D ∈ topGen ⁡ ran ⁡ . ↾ 𝑡 A B
92 91 adantr ⊢ φ ∧ C = A → A D ∈ topGen ⁡ ran ⁡ . ↾ 𝑡 A B
93 simpr ⊢ φ ∧ C = A → C = A
94 93 oveq1d ⊢ φ ∧ C = A → C D = A D
95 11 a1i ⊢ φ → J = TopOpen ⁡ ℂ fld ↾ 𝑡 A B
96 32 a1i ⊢ φ → TopOpen ⁡ ℂ fld ∈ Top
97 icossre ⊢ A ∈ ℝ ∧ B ∈ ℝ * → A B ⊆ ℝ
98 1 57 97 syl2anc ⊢ φ → A B ⊆ ℝ
99 reex ⊢ ℝ ∈ V
100 99 a1i ⊢ φ → ℝ ∈ V
101 restabs ⊢ TopOpen ⁡ ℂ fld ∈ Top ∧ A B ⊆ ℝ ∧ ℝ ∈ V → TopOpen ⁡ ℂ fld ↾ 𝑡 ℝ ↾ 𝑡 A B = TopOpen ⁡ ℂ fld ↾ 𝑡 A B
102 96 98 100 101 syl3anc ⊢ φ → TopOpen ⁡ ℂ fld ↾ 𝑡 ℝ ↾ 𝑡 A B = TopOpen ⁡ ℂ fld ↾ 𝑡 A B
103 tgioo4 ⊢ topGen ⁡ ran ⁡ . = TopOpen ⁡ ℂ fld ↾ 𝑡 ℝ
104 103 eqcomi ⊢ TopOpen ⁡ ℂ fld ↾ 𝑡 ℝ = topGen ⁡ ran ⁡ .
105 104 oveq1i ⊢ TopOpen ⁡ ℂ fld ↾ 𝑡 ℝ ↾ 𝑡 A B = topGen ⁡ ran ⁡ . ↾ 𝑡 A B
106 105 a1i ⊢ φ → TopOpen ⁡ ℂ fld ↾ 𝑡 ℝ ↾ 𝑡 A B = topGen ⁡ ran ⁡ . ↾ 𝑡 A B
107 95 102 106 3eqtr2d ⊢ φ → J = topGen ⁡ ran ⁡ . ↾ 𝑡 A B
108 107 adantr ⊢ φ ∧ C = A → J = topGen ⁡ ran ⁡ . ↾ 𝑡 A B
109 92 94 108 3eltr4d ⊢ φ ∧ C = A → C D ∈ J
110 isopn3i ⊢ J ∈ Top ∧ C D ∈ J → int ⁡ J ⁡ C D = C D
111 37 109 110 syl2anc ⊢ φ ∧ C = A → int ⁡ J ⁡ C D = C D
112 31 111 eleqtrrd ⊢ φ ∧ C = A → C ∈ int ⁡ J ⁡ C D
113 id ⊢ C = A → C = A
114 113 eqcomd ⊢ C = A → A = C
115 114 adantl ⊢ φ ∧ C = A → A = C
116 uncom ⊢ A B ∪ A = A ∪ A B
117 1 rexrd ⊢ φ → A ∈ ℝ *
118 snunioo ⊢ A ∈ ℝ * ∧ B ∈ ℝ * ∧ A < B → A ∪ A B = A B
119 117 57 3 118 syl3anc ⊢ φ → A ∪ A B = A B
120 116 119 eqtrid ⊢ φ → A B ∪ A = A B
121 120 adantr ⊢ φ ∧ C = A → A B ∪ A = A B
122 121 oveq2d ⊢ φ ∧ C = A → TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∪ A = TopOpen ⁡ ℂ fld ↾ 𝑡 A B
123 122 11 eqtr4di ⊢ φ ∧ C = A → TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∪ A = J
124 123 fveq2d ⊢ φ ∧ C = A → int ⁡ TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∪ A = int ⁡ J
125 uncom ⊢ C D ∪ A = A ∪ C D
126 sneq ⊢ C = A → C = A
127 126 eqcomd ⊢ C = A → A = C
128 127 uneq1d ⊢ C = A → A ∪ C D = C ∪ C D
129 125 128 eqtrid ⊢ C = A → C D ∪ A = C ∪ C D
130 6 rexrd ⊢ φ → C ∈ ℝ *
131 snunioo ⊢ C ∈ ℝ * ∧ D ∈ ℝ * ∧ C < D → C ∪ C D = C D
132 130 27 8 131 syl3anc ⊢ φ → C ∪ C D = C D
133 129 132 sylan9eqr ⊢ φ ∧ C = A → C D ∪ A = C D
134 124 133 fveq12d ⊢ φ ∧ C = A → int ⁡ TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∪ A ⁡ C D ∪ A = int ⁡ J ⁡ C D
135 112 115 134 3eltr4d ⊢ φ ∧ C = A → A ∈ int ⁡ TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∪ A ⁡ C D ∪ A
136 20 21 23 24 25 135 limcres ⊢ φ ∧ C = A → F ↾ C D lim ℂ A = F lim ℂ A
137 17 136 eqtr2d ⊢ φ ∧ C = A → F lim ℂ A = F ↾ C D lim ℂ C
138 12 15 137 3eltr3d ⊢ φ ∧ C = A → Y ∈ F ↾ C D lim ℂ C
139 limcresi ⊢ F lim ℂ C ⊆ F ↾ C D lim ℂ C
140 iffalse ⊢ ¬ C = A → if C = A R F ⁡ C = F ⁡ C
141 10 140 eqtrid ⊢ ¬ C = A → Y = F ⁡ C
142 141 adantl ⊢ φ ∧ ¬ C = A → Y = F ⁡ C
143 ssid ⊢ ℂ ⊆ ℂ
144 143 a1i ⊢ φ → ℂ ⊆ ℂ
145 eqid ⊢ TopOpen ⁡ ℂ fld ↾ 𝑡 A B = TopOpen ⁡ ℂ fld ↾ 𝑡 A B
146 unicntop ⊢ ℂ = ⋃ TopOpen ⁡ ℂ fld
147 146 restid ⊢ TopOpen ⁡ ℂ fld ∈ Top → TopOpen ⁡ ℂ fld ↾ 𝑡 ℂ = TopOpen ⁡ ℂ fld
148 32 147 ax-mp ⊢ TopOpen ⁡ ℂ fld ↾ 𝑡 ℂ = TopOpen ⁡ ℂ fld
149 148 eqcomi ⊢ TopOpen ⁡ ℂ fld = TopOpen ⁡ ℂ fld ↾ 𝑡 ℂ
150 24 145 149 cncfcn ⊢ A B ⊆ ℂ ∧ ℂ ⊆ ℂ → A B ⟶cn ℂ = TopOpen ⁡ ℂ fld ↾ 𝑡 A B Cn TopOpen ⁡ ℂ fld
151 22 144 150 sylancr ⊢ φ → A B ⟶cn ℂ = TopOpen ⁡ ℂ fld ↾ 𝑡 A B Cn TopOpen ⁡ ℂ fld
152 4 151 eleqtrd ⊢ φ → F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B Cn TopOpen ⁡ ℂ fld
153 24 cnfldtopon ⊢ TopOpen ⁡ ℂ fld ∈ TopOn ⁡ ℂ
154 resttopon ⊢ TopOpen ⁡ ℂ fld ∈ TopOn ⁡ ℂ ∧ A B ⊆ ℂ → TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∈ TopOn ⁡ A B
155 153 22 154 mp2an ⊢ TopOpen ⁡ ℂ fld ↾ 𝑡 A B ∈ TopOn ⁡ A B
156 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
157 155 153 156 mp2an ⊢ 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
158 152 157 sylib ⊢ φ → F : A B ⟶ ℂ ∧ ∀ x ∈ A B F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ x
159 158 simprd ⊢ φ → ∀ x ∈ A B F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ x
160 159 adantr ⊢ φ ∧ ¬ C = A → ∀ x ∈ A B F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ x
161 117 adantr ⊢ φ ∧ ¬ C = A → A ∈ ℝ *
162 57 adantr ⊢ φ ∧ ¬ C = A → B ∈ ℝ *
163 6 adantr ⊢ φ ∧ ¬ C = A → C ∈ ℝ
164 1 adantr ⊢ φ ∧ ¬ C = A → A ∈ ℝ
165 53 simpld ⊢ φ → A ≤ C
166 165 adantr ⊢ φ ∧ ¬ C = A → A ≤ C
167 113 eqcoms ⊢ A = C → C = A
168 167 necon3bi ⊢ ¬ C = A → A ≠ C
169 168 adantl ⊢ φ ∧ ¬ C = A → A ≠ C
170 169 necomd ⊢ φ ∧ ¬ C = A → C ≠ A
171 164 163 166 170 leneltd ⊢ φ ∧ ¬ C = A → A < C
172 6 7 2 8 54 ltletrd ⊢ φ → C < B
173 172 adantr ⊢ φ ∧ ¬ C = A → C < B
174 161 162 163 171 173 eliood ⊢ φ ∧ ¬ C = A → C ∈ A B
175 fveq2 ⊢ x = C → TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ x = TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ C
176 175 eleq2d ⊢ x = C → F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ x ↔ F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ C
177 176 rspccva ⊢ ∀ x ∈ A B F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ x ∧ C ∈ A B → F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ C
178 160 174 177 syl2anc ⊢ φ ∧ ¬ C = A → F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ C
179 24 145 cnplimc ⊢ A B ⊆ ℂ ∧ C ∈ A B → F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ C ↔ F : A B ⟶ ℂ ∧ F ⁡ C ∈ F lim ℂ C
180 22 174 179 sylancr ⊢ φ ∧ ¬ C = A → F ∈ TopOpen ⁡ ℂ fld ↾ 𝑡 A B CnP TopOpen ⁡ ℂ fld ⁡ C ↔ F : A B ⟶ ℂ ∧ F ⁡ C ∈ F lim ℂ C
181 178 180 mpbid ⊢ φ ∧ ¬ C = A → F : A B ⟶ ℂ ∧ F ⁡ C ∈ F lim ℂ C
182 181 simprd ⊢ φ ∧ ¬ C = A → F ⁡ C ∈ F lim ℂ C
183 142 182 eqeltrd ⊢ φ ∧ ¬ C = A → Y ∈ F lim ℂ C
184 139 183 sselid ⊢ φ ∧ ¬ C = A → Y ∈ F ↾ C D lim ℂ C
185 138 184 pm2.61dan ⊢ φ → Y ∈ F ↾ C D lim ℂ C