Metamath Proof Explorer


Theorem fourierdlem114

Description: Fourier series convergence for periodic, piecewise smooth functions. (Contributed by Glauco Siliprandi, 11-Dec-2019)

Ref Expression
Hypotheses fourierdlem114.f ( 𝜑𝐹 : ℝ ⟶ ℝ )
fourierdlem114.t 𝑇 = ( 2 · π )
fourierdlem114.per ( ( 𝜑𝑥 ∈ ℝ ) → ( 𝐹 ‘ ( 𝑥 + 𝑇 ) ) = ( 𝐹𝑥 ) )
fourierdlem114.g 𝐺 = ( ( ℝ D 𝐹 ) ↾ ( - π (,) π ) )
fourierdlem114.dmdv ( 𝜑 → ( ( - π (,) π ) ∖ dom 𝐺 ) ∈ Fin )
fourierdlem114.gcn ( 𝜑𝐺 ∈ ( dom 𝐺cn→ ℂ ) )
fourierdlem114.rlim ( ( 𝜑𝑥 ∈ ( ( - π [,) π ) ∖ dom 𝐺 ) ) → ( ( 𝐺 ↾ ( 𝑥 (,) +∞ ) ) lim 𝑥 ) ≠ ∅ )
fourierdlem114.llim ( ( 𝜑𝑥 ∈ ( ( - π (,] π ) ∖ dom 𝐺 ) ) → ( ( 𝐺 ↾ ( -∞ (,) 𝑥 ) ) lim 𝑥 ) ≠ ∅ )
fourierdlem114.x ( 𝜑𝑋 ∈ ℝ )
fourierdlem114.l ( 𝜑𝐿 ∈ ( ( 𝐹 ↾ ( -∞ (,) 𝑋 ) ) lim 𝑋 ) )
fourierdlem114.r ( 𝜑𝑅 ∈ ( ( 𝐹 ↾ ( 𝑋 (,) +∞ ) ) lim 𝑋 ) )
fourierdlem114.a 𝐴 = ( 𝑛 ∈ ℕ0 ↦ ( ∫ ( - π (,) π ) ( ( 𝐹𝑥 ) · ( cos ‘ ( 𝑛 · 𝑥 ) ) ) d 𝑥 / π ) )
fourierdlem114.b 𝐵 = ( 𝑛 ∈ ℕ ↦ ( ∫ ( - π (,) π ) ( ( 𝐹𝑥 ) · ( sin ‘ ( 𝑛 · 𝑥 ) ) ) d 𝑥 / π ) )
fourierdlem114.s 𝑆 = ( 𝑛 ∈ ℕ ↦ ( ( ( 𝐴𝑛 ) · ( cos ‘ ( 𝑛 · 𝑋 ) ) ) + ( ( 𝐵𝑛 ) · ( sin ‘ ( 𝑛 · 𝑋 ) ) ) ) )
fourierdlem114.p 𝑃 = ( 𝑛 ∈ ℕ ↦ { 𝑝 ∈ ( ℝ ↑m ( 0 ... 𝑛 ) ) ∣ ( ( ( 𝑝 ‘ 0 ) = - π ∧ ( 𝑝𝑛 ) = π ) ∧ ∀ 𝑖 ∈ ( 0 ..^ 𝑛 ) ( 𝑝𝑖 ) < ( 𝑝 ‘ ( 𝑖 + 1 ) ) ) } )
fourierdlem114.e 𝐸 = ( 𝑥 ∈ ℝ ↦ ( 𝑥 + ( ( ⌊ ‘ ( ( π − 𝑥 ) / 𝑇 ) ) · 𝑇 ) ) )
fourierdlem114.h 𝐻 = ( { - π , π , ( 𝐸𝑋 ) } ∪ ( ( - π [,] π ) ∖ dom 𝐺 ) )
fourierdlem114.m 𝑀 = ( ( ♯ ‘ 𝐻 ) − 1 )
fourierdlem114.q 𝑄 = ( ℩ 𝑔 𝑔 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) )
Assertion fourierdlem114 ( 𝜑 → ( seq 1 ( + , 𝑆 ) ⇝ ( ( ( 𝐿 + 𝑅 ) / 2 ) − ( ( 𝐴 ‘ 0 ) / 2 ) ) ∧ ( ( ( 𝐴 ‘ 0 ) / 2 ) + Σ 𝑛 ∈ ℕ ( ( ( 𝐴𝑛 ) · ( cos ‘ ( 𝑛 · 𝑋 ) ) ) + ( ( 𝐵𝑛 ) · ( sin ‘ ( 𝑛 · 𝑋 ) ) ) ) ) = ( ( 𝐿 + 𝑅 ) / 2 ) ) )

Proof

Step Hyp Ref Expression
1 fourierdlem114.f ( 𝜑𝐹 : ℝ ⟶ ℝ )
2 fourierdlem114.t 𝑇 = ( 2 · π )
3 fourierdlem114.per ( ( 𝜑𝑥 ∈ ℝ ) → ( 𝐹 ‘ ( 𝑥 + 𝑇 ) ) = ( 𝐹𝑥 ) )
4 fourierdlem114.g 𝐺 = ( ( ℝ D 𝐹 ) ↾ ( - π (,) π ) )
5 fourierdlem114.dmdv ( 𝜑 → ( ( - π (,) π ) ∖ dom 𝐺 ) ∈ Fin )
6 fourierdlem114.gcn ( 𝜑𝐺 ∈ ( dom 𝐺cn→ ℂ ) )
7 fourierdlem114.rlim ( ( 𝜑𝑥 ∈ ( ( - π [,) π ) ∖ dom 𝐺 ) ) → ( ( 𝐺 ↾ ( 𝑥 (,) +∞ ) ) lim 𝑥 ) ≠ ∅ )
8 fourierdlem114.llim ( ( 𝜑𝑥 ∈ ( ( - π (,] π ) ∖ dom 𝐺 ) ) → ( ( 𝐺 ↾ ( -∞ (,) 𝑥 ) ) lim 𝑥 ) ≠ ∅ )
9 fourierdlem114.x ( 𝜑𝑋 ∈ ℝ )
10 fourierdlem114.l ( 𝜑𝐿 ∈ ( ( 𝐹 ↾ ( -∞ (,) 𝑋 ) ) lim 𝑋 ) )
11 fourierdlem114.r ( 𝜑𝑅 ∈ ( ( 𝐹 ↾ ( 𝑋 (,) +∞ ) ) lim 𝑋 ) )
12 fourierdlem114.a 𝐴 = ( 𝑛 ∈ ℕ0 ↦ ( ∫ ( - π (,) π ) ( ( 𝐹𝑥 ) · ( cos ‘ ( 𝑛 · 𝑥 ) ) ) d 𝑥 / π ) )
13 fourierdlem114.b 𝐵 = ( 𝑛 ∈ ℕ ↦ ( ∫ ( - π (,) π ) ( ( 𝐹𝑥 ) · ( sin ‘ ( 𝑛 · 𝑥 ) ) ) d 𝑥 / π ) )
14 fourierdlem114.s 𝑆 = ( 𝑛 ∈ ℕ ↦ ( ( ( 𝐴𝑛 ) · ( cos ‘ ( 𝑛 · 𝑋 ) ) ) + ( ( 𝐵𝑛 ) · ( sin ‘ ( 𝑛 · 𝑋 ) ) ) ) )
15 fourierdlem114.p 𝑃 = ( 𝑛 ∈ ℕ ↦ { 𝑝 ∈ ( ℝ ↑m ( 0 ... 𝑛 ) ) ∣ ( ( ( 𝑝 ‘ 0 ) = - π ∧ ( 𝑝𝑛 ) = π ) ∧ ∀ 𝑖 ∈ ( 0 ..^ 𝑛 ) ( 𝑝𝑖 ) < ( 𝑝 ‘ ( 𝑖 + 1 ) ) ) } )
16 fourierdlem114.e 𝐸 = ( 𝑥 ∈ ℝ ↦ ( 𝑥 + ( ( ⌊ ‘ ( ( π − 𝑥 ) / 𝑇 ) ) · 𝑇 ) ) )
17 fourierdlem114.h 𝐻 = ( { - π , π , ( 𝐸𝑋 ) } ∪ ( ( - π [,] π ) ∖ dom 𝐺 ) )
18 fourierdlem114.m 𝑀 = ( ( ♯ ‘ 𝐻 ) − 1 )
19 fourierdlem114.q 𝑄 = ( ℩ 𝑔 𝑔 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) )
20 2z 2 ∈ ℤ
21 20 a1i ( 𝜑 → 2 ∈ ℤ )
22 tpfi { - π , π , ( 𝐸𝑋 ) } ∈ Fin
23 22 a1i ( 𝜑 → { - π , π , ( 𝐸𝑋 ) } ∈ Fin )
24 pire π ∈ ℝ
25 24 renegcli - π ∈ ℝ
26 25 rexri - π ∈ ℝ*
27 24 rexri π ∈ ℝ*
28 negpilt0 - π < 0
29 pipos 0 < π
30 0re 0 ∈ ℝ
31 25 30 24 lttri ( ( - π < 0 ∧ 0 < π ) → - π < π )
32 28 29 31 mp2an - π < π
33 25 24 32 ltleii - π ≤ π
34 prunioo ( ( - π ∈ ℝ* ∧ π ∈ ℝ* ∧ - π ≤ π ) → ( ( - π (,) π ) ∪ { - π , π } ) = ( - π [,] π ) )
35 26 27 33 34 mp3an ( ( - π (,) π ) ∪ { - π , π } ) = ( - π [,] π )
36 35 difeq1i ( ( ( - π (,) π ) ∪ { - π , π } ) ∖ dom 𝐺 ) = ( ( - π [,] π ) ∖ dom 𝐺 )
37 difundir ( ( ( - π (,) π ) ∪ { - π , π } ) ∖ dom 𝐺 ) = ( ( ( - π (,) π ) ∖ dom 𝐺 ) ∪ ( { - π , π } ∖ dom 𝐺 ) )
38 36 37 eqtr3i ( ( - π [,] π ) ∖ dom 𝐺 ) = ( ( ( - π (,) π ) ∖ dom 𝐺 ) ∪ ( { - π , π } ∖ dom 𝐺 ) )
39 prfi { - π , π } ∈ Fin
40 diffi ( { - π , π } ∈ Fin → ( { - π , π } ∖ dom 𝐺 ) ∈ Fin )
41 39 40 mp1i ( 𝜑 → ( { - π , π } ∖ dom 𝐺 ) ∈ Fin )
42 unfi ( ( ( ( - π (,) π ) ∖ dom 𝐺 ) ∈ Fin ∧ ( { - π , π } ∖ dom 𝐺 ) ∈ Fin ) → ( ( ( - π (,) π ) ∖ dom 𝐺 ) ∪ ( { - π , π } ∖ dom 𝐺 ) ) ∈ Fin )
43 5 41 42 syl2anc ( 𝜑 → ( ( ( - π (,) π ) ∖ dom 𝐺 ) ∪ ( { - π , π } ∖ dom 𝐺 ) ) ∈ Fin )
44 38 43 eqeltrid ( 𝜑 → ( ( - π [,] π ) ∖ dom 𝐺 ) ∈ Fin )
45 unfi ( ( { - π , π , ( 𝐸𝑋 ) } ∈ Fin ∧ ( ( - π [,] π ) ∖ dom 𝐺 ) ∈ Fin ) → ( { - π , π , ( 𝐸𝑋 ) } ∪ ( ( - π [,] π ) ∖ dom 𝐺 ) ) ∈ Fin )
46 23 44 45 syl2anc ( 𝜑 → ( { - π , π , ( 𝐸𝑋 ) } ∪ ( ( - π [,] π ) ∖ dom 𝐺 ) ) ∈ Fin )
47 17 46 eqeltrid ( 𝜑𝐻 ∈ Fin )
48 hashcl ( 𝐻 ∈ Fin → ( ♯ ‘ 𝐻 ) ∈ ℕ0 )
49 47 48 syl ( 𝜑 → ( ♯ ‘ 𝐻 ) ∈ ℕ0 )
50 49 nn0zd ( 𝜑 → ( ♯ ‘ 𝐻 ) ∈ ℤ )
51 25 32 ltneii - π ≠ π
52 hashprg ( ( - π ∈ ℝ ∧ π ∈ ℝ ) → ( - π ≠ π ↔ ( ♯ ‘ { - π , π } ) = 2 ) )
53 25 24 52 mp2an ( - π ≠ π ↔ ( ♯ ‘ { - π , π } ) = 2 )
54 51 53 mpbi ( ♯ ‘ { - π , π } ) = 2
55 22 elexi { - π , π , ( 𝐸𝑋 ) } ∈ V
56 ovex ( - π [,] π ) ∈ V
57 difexg ( ( - π [,] π ) ∈ V → ( ( - π [,] π ) ∖ dom 𝐺 ) ∈ V )
58 56 57 ax-mp ( ( - π [,] π ) ∖ dom 𝐺 ) ∈ V
59 55 58 unex ( { - π , π , ( 𝐸𝑋 ) } ∪ ( ( - π [,] π ) ∖ dom 𝐺 ) ) ∈ V
60 17 59 eqeltri 𝐻 ∈ V
61 negex - π ∈ V
62 61 tpid1 - π ∈ { - π , π , ( 𝐸𝑋 ) }
63 24 elexi π ∈ V
64 63 tpid2 π ∈ { - π , π , ( 𝐸𝑋 ) }
65 prssi ( ( - π ∈ { - π , π , ( 𝐸𝑋 ) } ∧ π ∈ { - π , π , ( 𝐸𝑋 ) } ) → { - π , π } ⊆ { - π , π , ( 𝐸𝑋 ) } )
66 62 64 65 mp2an { - π , π } ⊆ { - π , π , ( 𝐸𝑋 ) }
67 ssun1 { - π , π , ( 𝐸𝑋 ) } ⊆ ( { - π , π , ( 𝐸𝑋 ) } ∪ ( ( - π [,] π ) ∖ dom 𝐺 ) )
68 67 17 sseqtrri { - π , π , ( 𝐸𝑋 ) } ⊆ 𝐻
69 66 68 sstri { - π , π } ⊆ 𝐻
70 hashss ( ( 𝐻 ∈ V ∧ { - π , π } ⊆ 𝐻 ) → ( ♯ ‘ { - π , π } ) ≤ ( ♯ ‘ 𝐻 ) )
71 60 69 70 mp2an ( ♯ ‘ { - π , π } ) ≤ ( ♯ ‘ 𝐻 )
72 71 a1i ( 𝜑 → ( ♯ ‘ { - π , π } ) ≤ ( ♯ ‘ 𝐻 ) )
73 54 72 eqbrtrrid ( 𝜑 → 2 ≤ ( ♯ ‘ 𝐻 ) )
74 eluz2 ( ( ♯ ‘ 𝐻 ) ∈ ( ℤ ‘ 2 ) ↔ ( 2 ∈ ℤ ∧ ( ♯ ‘ 𝐻 ) ∈ ℤ ∧ 2 ≤ ( ♯ ‘ 𝐻 ) ) )
75 21 50 73 74 syl3anbrc ( 𝜑 → ( ♯ ‘ 𝐻 ) ∈ ( ℤ ‘ 2 ) )
76 uz2m1nn ( ( ♯ ‘ 𝐻 ) ∈ ( ℤ ‘ 2 ) → ( ( ♯ ‘ 𝐻 ) − 1 ) ∈ ℕ )
77 75 76 syl ( 𝜑 → ( ( ♯ ‘ 𝐻 ) − 1 ) ∈ ℕ )
78 18 77 eqeltrid ( 𝜑𝑀 ∈ ℕ )
79 25 a1i ( 𝜑 → - π ∈ ℝ )
80 24 a1i ( 𝜑 → π ∈ ℝ )
81 negpitopissre ( - π (,] π ) ⊆ ℝ
82 32 a1i ( 𝜑 → - π < π )
83 picn π ∈ ℂ
84 83 2timesi ( 2 · π ) = ( π + π )
85 83 83 subnegi ( π − - π ) = ( π + π )
86 84 2 85 3eqtr4i 𝑇 = ( π − - π )
87 79 80 82 86 16 fourierdlem4 ( 𝜑𝐸 : ℝ ⟶ ( - π (,] π ) )
88 87 9 ffvelrnd ( 𝜑 → ( 𝐸𝑋 ) ∈ ( - π (,] π ) )
89 81 88 sseldi ( 𝜑 → ( 𝐸𝑋 ) ∈ ℝ )
90 79 80 89 3jca ( 𝜑 → ( - π ∈ ℝ ∧ π ∈ ℝ ∧ ( 𝐸𝑋 ) ∈ ℝ ) )
91 fvex ( 𝐸𝑋 ) ∈ V
92 61 63 91 tpss ( ( - π ∈ ℝ ∧ π ∈ ℝ ∧ ( 𝐸𝑋 ) ∈ ℝ ) ↔ { - π , π , ( 𝐸𝑋 ) } ⊆ ℝ )
93 90 92 sylib ( 𝜑 → { - π , π , ( 𝐸𝑋 ) } ⊆ ℝ )
94 iccssre ( ( - π ∈ ℝ ∧ π ∈ ℝ ) → ( - π [,] π ) ⊆ ℝ )
95 25 24 94 mp2an ( - π [,] π ) ⊆ ℝ
96 ssdifss ( ( - π [,] π ) ⊆ ℝ → ( ( - π [,] π ) ∖ dom 𝐺 ) ⊆ ℝ )
97 95 96 mp1i ( 𝜑 → ( ( - π [,] π ) ∖ dom 𝐺 ) ⊆ ℝ )
98 93 97 unssd ( 𝜑 → ( { - π , π , ( 𝐸𝑋 ) } ∪ ( ( - π [,] π ) ∖ dom 𝐺 ) ) ⊆ ℝ )
99 17 98 eqsstrid ( 𝜑𝐻 ⊆ ℝ )
100 47 99 19 18 fourierdlem36 ( 𝜑𝑄 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) )
101 isof1o ( 𝑄 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) → 𝑄 : ( 0 ... 𝑀 ) –1-1-onto𝐻 )
102 f1of ( 𝑄 : ( 0 ... 𝑀 ) –1-1-onto𝐻𝑄 : ( 0 ... 𝑀 ) ⟶ 𝐻 )
103 100 101 102 3syl ( 𝜑𝑄 : ( 0 ... 𝑀 ) ⟶ 𝐻 )
104 103 99 fssd ( 𝜑𝑄 : ( 0 ... 𝑀 ) ⟶ ℝ )
105 reex ℝ ∈ V
106 ovex ( 0 ... 𝑀 ) ∈ V
107 105 106 elmap ( 𝑄 ∈ ( ℝ ↑m ( 0 ... 𝑀 ) ) ↔ 𝑄 : ( 0 ... 𝑀 ) ⟶ ℝ )
108 104 107 sylibr ( 𝜑𝑄 ∈ ( ℝ ↑m ( 0 ... 𝑀 ) ) )
109 fveq2 ( 0 = 𝑖 → ( 𝑄 ‘ 0 ) = ( 𝑄𝑖 ) )
110 109 adantl ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 = 𝑖 ) → ( 𝑄 ‘ 0 ) = ( 𝑄𝑖 ) )
111 104 ffvelrnda ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) → ( 𝑄𝑖 ) ∈ ℝ )
112 111 leidd ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) → ( 𝑄𝑖 ) ≤ ( 𝑄𝑖 ) )
113 112 adantr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 = 𝑖 ) → ( 𝑄𝑖 ) ≤ ( 𝑄𝑖 ) )
114 110 113 eqbrtrd ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 = 𝑖 ) → ( 𝑄 ‘ 0 ) ≤ ( 𝑄𝑖 ) )
115 elfzelz ( 𝑖 ∈ ( 0 ... 𝑀 ) → 𝑖 ∈ ℤ )
116 115 zred ( 𝑖 ∈ ( 0 ... 𝑀 ) → 𝑖 ∈ ℝ )
117 116 ad2antlr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 0 = 𝑖 ) → 𝑖 ∈ ℝ )
118 elfzle1 ( 𝑖 ∈ ( 0 ... 𝑀 ) → 0 ≤ 𝑖 )
119 118 ad2antlr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 0 = 𝑖 ) → 0 ≤ 𝑖 )
120 neqne ( ¬ 0 = 𝑖 → 0 ≠ 𝑖 )
121 120 necomd ( ¬ 0 = 𝑖𝑖 ≠ 0 )
122 121 adantl ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 0 = 𝑖 ) → 𝑖 ≠ 0 )
123 117 119 122 ne0gt0d ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 0 = 𝑖 ) → 0 < 𝑖 )
124 nnssnn0 ℕ ⊆ ℕ0
125 nn0uz 0 = ( ℤ ‘ 0 )
126 124 125 sseqtri ℕ ⊆ ( ℤ ‘ 0 )
127 126 78 sseldi ( 𝜑𝑀 ∈ ( ℤ ‘ 0 ) )
128 eluzfz1 ( 𝑀 ∈ ( ℤ ‘ 0 ) → 0 ∈ ( 0 ... 𝑀 ) )
129 127 128 syl ( 𝜑 → 0 ∈ ( 0 ... 𝑀 ) )
130 103 129 ffvelrnd ( 𝜑 → ( 𝑄 ‘ 0 ) ∈ 𝐻 )
131 99 130 sseldd ( 𝜑 → ( 𝑄 ‘ 0 ) ∈ ℝ )
132 131 ad2antrr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 < 𝑖 ) → ( 𝑄 ‘ 0 ) ∈ ℝ )
133 111 adantr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 < 𝑖 ) → ( 𝑄𝑖 ) ∈ ℝ )
134 simpr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 < 𝑖 ) → 0 < 𝑖 )
135 100 ad2antrr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 < 𝑖 ) → 𝑄 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) )
136 129 anim1i ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) → ( 0 ∈ ( 0 ... 𝑀 ) ∧ 𝑖 ∈ ( 0 ... 𝑀 ) ) )
137 136 adantr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 < 𝑖 ) → ( 0 ∈ ( 0 ... 𝑀 ) ∧ 𝑖 ∈ ( 0 ... 𝑀 ) ) )
138 isorel ( ( 𝑄 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) ∧ ( 0 ∈ ( 0 ... 𝑀 ) ∧ 𝑖 ∈ ( 0 ... 𝑀 ) ) ) → ( 0 < 𝑖 ↔ ( 𝑄 ‘ 0 ) < ( 𝑄𝑖 ) ) )
139 135 137 138 syl2anc ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 < 𝑖 ) → ( 0 < 𝑖 ↔ ( 𝑄 ‘ 0 ) < ( 𝑄𝑖 ) ) )
140 134 139 mpbid ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 < 𝑖 ) → ( 𝑄 ‘ 0 ) < ( 𝑄𝑖 ) )
141 132 133 140 ltled ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 < 𝑖 ) → ( 𝑄 ‘ 0 ) ≤ ( 𝑄𝑖 ) )
142 123 141 syldan ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 0 = 𝑖 ) → ( 𝑄 ‘ 0 ) ≤ ( 𝑄𝑖 ) )
143 114 142 pm2.61dan ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) → ( 𝑄 ‘ 0 ) ≤ ( 𝑄𝑖 ) )
144 143 adantr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ( 𝑄𝑖 ) = - π ) → ( 𝑄 ‘ 0 ) ≤ ( 𝑄𝑖 ) )
145 simpr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ( 𝑄𝑖 ) = - π ) → ( 𝑄𝑖 ) = - π )
146 144 145 breqtrd ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ( 𝑄𝑖 ) = - π ) → ( 𝑄 ‘ 0 ) ≤ - π )
147 79 rexrd ( 𝜑 → - π ∈ ℝ* )
148 80 rexrd ( 𝜑 → π ∈ ℝ* )
149 lbicc2 ( ( - π ∈ ℝ* ∧ π ∈ ℝ* ∧ - π ≤ π ) → - π ∈ ( - π [,] π ) )
150 26 27 33 149 mp3an - π ∈ ( - π [,] π )
151 150 a1i ( 𝜑 → - π ∈ ( - π [,] π ) )
152 ubicc2 ( ( - π ∈ ℝ* ∧ π ∈ ℝ* ∧ - π ≤ π ) → π ∈ ( - π [,] π ) )
153 26 27 33 152 mp3an π ∈ ( - π [,] π )
154 153 a1i ( 𝜑 → π ∈ ( - π [,] π ) )
155 iocssicc ( - π (,] π ) ⊆ ( - π [,] π )
156 155 88 sseldi ( 𝜑 → ( 𝐸𝑋 ) ∈ ( - π [,] π ) )
157 tpssi ( ( - π ∈ ( - π [,] π ) ∧ π ∈ ( - π [,] π ) ∧ ( 𝐸𝑋 ) ∈ ( - π [,] π ) ) → { - π , π , ( 𝐸𝑋 ) } ⊆ ( - π [,] π ) )
158 151 154 156 157 syl3anc ( 𝜑 → { - π , π , ( 𝐸𝑋 ) } ⊆ ( - π [,] π ) )
159 difssd ( 𝜑 → ( ( - π [,] π ) ∖ dom 𝐺 ) ⊆ ( - π [,] π ) )
160 158 159 unssd ( 𝜑 → ( { - π , π , ( 𝐸𝑋 ) } ∪ ( ( - π [,] π ) ∖ dom 𝐺 ) ) ⊆ ( - π [,] π ) )
161 17 160 eqsstrid ( 𝜑𝐻 ⊆ ( - π [,] π ) )
162 161 130 sseldd ( 𝜑 → ( 𝑄 ‘ 0 ) ∈ ( - π [,] π ) )
163 iccgelb ( ( - π ∈ ℝ* ∧ π ∈ ℝ* ∧ ( 𝑄 ‘ 0 ) ∈ ( - π [,] π ) ) → - π ≤ ( 𝑄 ‘ 0 ) )
164 147 148 162 163 syl3anc ( 𝜑 → - π ≤ ( 𝑄 ‘ 0 ) )
165 164 ad2antrr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ( 𝑄𝑖 ) = - π ) → - π ≤ ( 𝑄 ‘ 0 ) )
166 131 ad2antrr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ( 𝑄𝑖 ) = - π ) → ( 𝑄 ‘ 0 ) ∈ ℝ )
167 25 a1i ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ( 𝑄𝑖 ) = - π ) → - π ∈ ℝ )
168 166 167 letri3d ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ( 𝑄𝑖 ) = - π ) → ( ( 𝑄 ‘ 0 ) = - π ↔ ( ( 𝑄 ‘ 0 ) ≤ - π ∧ - π ≤ ( 𝑄 ‘ 0 ) ) ) )
169 146 165 168 mpbir2and ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ( 𝑄𝑖 ) = - π ) → ( 𝑄 ‘ 0 ) = - π )
170 68 62 sselii - π ∈ 𝐻
171 f1ofo ( 𝑄 : ( 0 ... 𝑀 ) –1-1-onto𝐻𝑄 : ( 0 ... 𝑀 ) –onto𝐻 )
172 101 171 syl ( 𝑄 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) → 𝑄 : ( 0 ... 𝑀 ) –onto𝐻 )
173 forn ( 𝑄 : ( 0 ... 𝑀 ) –onto𝐻 → ran 𝑄 = 𝐻 )
174 100 172 173 3syl ( 𝜑 → ran 𝑄 = 𝐻 )
175 170 174 eleqtrrid ( 𝜑 → - π ∈ ran 𝑄 )
176 ffn ( 𝑄 : ( 0 ... 𝑀 ) ⟶ 𝐻𝑄 Fn ( 0 ... 𝑀 ) )
177 fvelrnb ( 𝑄 Fn ( 0 ... 𝑀 ) → ( - π ∈ ran 𝑄 ↔ ∃ 𝑖 ∈ ( 0 ... 𝑀 ) ( 𝑄𝑖 ) = - π ) )
178 103 176 177 3syl ( 𝜑 → ( - π ∈ ran 𝑄 ↔ ∃ 𝑖 ∈ ( 0 ... 𝑀 ) ( 𝑄𝑖 ) = - π ) )
179 175 178 mpbid ( 𝜑 → ∃ 𝑖 ∈ ( 0 ... 𝑀 ) ( 𝑄𝑖 ) = - π )
180 169 179 r19.29a ( 𝜑 → ( 𝑄 ‘ 0 ) = - π )
181 68 64 sselii π ∈ 𝐻
182 181 174 eleqtrrid ( 𝜑 → π ∈ ran 𝑄 )
183 fvelrnb ( 𝑄 Fn ( 0 ... 𝑀 ) → ( π ∈ ran 𝑄 ↔ ∃ 𝑖 ∈ ( 0 ... 𝑀 ) ( 𝑄𝑖 ) = π ) )
184 103 176 183 3syl ( 𝜑 → ( π ∈ ran 𝑄 ↔ ∃ 𝑖 ∈ ( 0 ... 𝑀 ) ( 𝑄𝑖 ) = π ) )
185 182 184 mpbid ( 𝜑 → ∃ 𝑖 ∈ ( 0 ... 𝑀 ) ( 𝑄𝑖 ) = π )
186 103 161 fssd ( 𝜑𝑄 : ( 0 ... 𝑀 ) ⟶ ( - π [,] π ) )
187 eluzfz2 ( 𝑀 ∈ ( ℤ ‘ 0 ) → 𝑀 ∈ ( 0 ... 𝑀 ) )
188 127 187 syl ( 𝜑𝑀 ∈ ( 0 ... 𝑀 ) )
189 186 188 ffvelrnd ( 𝜑 → ( 𝑄𝑀 ) ∈ ( - π [,] π ) )
190 iccleub ( ( - π ∈ ℝ* ∧ π ∈ ℝ* ∧ ( 𝑄𝑀 ) ∈ ( - π [,] π ) ) → ( 𝑄𝑀 ) ≤ π )
191 147 148 189 190 syl3anc ( 𝜑 → ( 𝑄𝑀 ) ≤ π )
192 191 3ad2ant1 ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑄𝑖 ) = π ) → ( 𝑄𝑀 ) ≤ π )
193 id ( ( 𝑄𝑖 ) = π → ( 𝑄𝑖 ) = π )
194 193 eqcomd ( ( 𝑄𝑖 ) = π → π = ( 𝑄𝑖 ) )
195 194 3ad2ant3 ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑄𝑖 ) = π ) → π = ( 𝑄𝑖 ) )
196 112 adantr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 = 𝑀 ) → ( 𝑄𝑖 ) ≤ ( 𝑄𝑖 ) )
197 fveq2 ( 𝑖 = 𝑀 → ( 𝑄𝑖 ) = ( 𝑄𝑀 ) )
198 197 adantl ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 = 𝑀 ) → ( 𝑄𝑖 ) = ( 𝑄𝑀 ) )
199 196 198 breqtrd ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 = 𝑀 ) → ( 𝑄𝑖 ) ≤ ( 𝑄𝑀 ) )
200 116 ad2antlr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 𝑖 = 𝑀 ) → 𝑖 ∈ ℝ )
201 elfzel2 ( 𝑖 ∈ ( 0 ... 𝑀 ) → 𝑀 ∈ ℤ )
202 201 zred ( 𝑖 ∈ ( 0 ... 𝑀 ) → 𝑀 ∈ ℝ )
203 202 ad2antlr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 𝑖 = 𝑀 ) → 𝑀 ∈ ℝ )
204 elfzle2 ( 𝑖 ∈ ( 0 ... 𝑀 ) → 𝑖𝑀 )
205 204 ad2antlr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 𝑖 = 𝑀 ) → 𝑖𝑀 )
206 neqne ( ¬ 𝑖 = 𝑀𝑖𝑀 )
207 206 necomd ( ¬ 𝑖 = 𝑀𝑀𝑖 )
208 207 adantl ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 𝑖 = 𝑀 ) → 𝑀𝑖 )
209 200 203 205 208 leneltd ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 𝑖 = 𝑀 ) → 𝑖 < 𝑀 )
210 111 adantr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 < 𝑀 ) → ( 𝑄𝑖 ) ∈ ℝ )
211 95 189 sseldi ( 𝜑 → ( 𝑄𝑀 ) ∈ ℝ )
212 211 ad2antrr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 < 𝑀 ) → ( 𝑄𝑀 ) ∈ ℝ )
213 simpr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 < 𝑀 ) → 𝑖 < 𝑀 )
214 100 ad2antrr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 < 𝑀 ) → 𝑄 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) )
215 simpr ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) → 𝑖 ∈ ( 0 ... 𝑀 ) )
216 188 adantr ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) → 𝑀 ∈ ( 0 ... 𝑀 ) )
217 215 216 jca ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) → ( 𝑖 ∈ ( 0 ... 𝑀 ) ∧ 𝑀 ∈ ( 0 ... 𝑀 ) ) )
218 217 adantr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 < 𝑀 ) → ( 𝑖 ∈ ( 0 ... 𝑀 ) ∧ 𝑀 ∈ ( 0 ... 𝑀 ) ) )
219 isorel ( ( 𝑄 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) ∧ ( 𝑖 ∈ ( 0 ... 𝑀 ) ∧ 𝑀 ∈ ( 0 ... 𝑀 ) ) ) → ( 𝑖 < 𝑀 ↔ ( 𝑄𝑖 ) < ( 𝑄𝑀 ) ) )
220 214 218 219 syl2anc ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 < 𝑀 ) → ( 𝑖 < 𝑀 ↔ ( 𝑄𝑖 ) < ( 𝑄𝑀 ) ) )
221 213 220 mpbid ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 < 𝑀 ) → ( 𝑄𝑖 ) < ( 𝑄𝑀 ) )
222 210 212 221 ltled ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 < 𝑀 ) → ( 𝑄𝑖 ) ≤ ( 𝑄𝑀 ) )
223 209 222 syldan ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 𝑖 = 𝑀 ) → ( 𝑄𝑖 ) ≤ ( 𝑄𝑀 ) )
224 199 223 pm2.61dan ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) → ( 𝑄𝑖 ) ≤ ( 𝑄𝑀 ) )
225 224 3adant3 ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑄𝑖 ) = π ) → ( 𝑄𝑖 ) ≤ ( 𝑄𝑀 ) )
226 195 225 eqbrtrd ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑄𝑖 ) = π ) → π ≤ ( 𝑄𝑀 ) )
227 211 3ad2ant1 ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑄𝑖 ) = π ) → ( 𝑄𝑀 ) ∈ ℝ )
228 24 a1i ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑄𝑖 ) = π ) → π ∈ ℝ )
229 227 228 letri3d ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑄𝑖 ) = π ) → ( ( 𝑄𝑀 ) = π ↔ ( ( 𝑄𝑀 ) ≤ π ∧ π ≤ ( 𝑄𝑀 ) ) ) )
230 192 226 229 mpbir2and ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑄𝑖 ) = π ) → ( 𝑄𝑀 ) = π )
231 230 rexlimdv3a ( 𝜑 → ( ∃ 𝑖 ∈ ( 0 ... 𝑀 ) ( 𝑄𝑖 ) = π → ( 𝑄𝑀 ) = π ) )
232 185 231 mpd ( 𝜑 → ( 𝑄𝑀 ) = π )
233 elfzoelz ( 𝑖 ∈ ( 0 ..^ 𝑀 ) → 𝑖 ∈ ℤ )
234 233 zred ( 𝑖 ∈ ( 0 ..^ 𝑀 ) → 𝑖 ∈ ℝ )
235 234 ltp1d ( 𝑖 ∈ ( 0 ..^ 𝑀 ) → 𝑖 < ( 𝑖 + 1 ) )
236 235 adantl ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → 𝑖 < ( 𝑖 + 1 ) )
237 elfzofz ( 𝑖 ∈ ( 0 ..^ 𝑀 ) → 𝑖 ∈ ( 0 ... 𝑀 ) )
238 fzofzp1 ( 𝑖 ∈ ( 0 ..^ 𝑀 ) → ( 𝑖 + 1 ) ∈ ( 0 ... 𝑀 ) )
239 237 238 jca ( 𝑖 ∈ ( 0 ..^ 𝑀 ) → ( 𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑖 + 1 ) ∈ ( 0 ... 𝑀 ) ) )
240 isorel ( ( 𝑄 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) ∧ ( 𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑖 + 1 ) ∈ ( 0 ... 𝑀 ) ) ) → ( 𝑖 < ( 𝑖 + 1 ) ↔ ( 𝑄𝑖 ) < ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) )
241 100 239 240 syl2an ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( 𝑖 < ( 𝑖 + 1 ) ↔ ( 𝑄𝑖 ) < ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) )
242 236 241 mpbid ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( 𝑄𝑖 ) < ( 𝑄 ‘ ( 𝑖 + 1 ) ) )
243 242 ralrimiva ( 𝜑 → ∀ 𝑖 ∈ ( 0 ..^ 𝑀 ) ( 𝑄𝑖 ) < ( 𝑄 ‘ ( 𝑖 + 1 ) ) )
244 180 232 243 jca31 ( 𝜑 → ( ( ( 𝑄 ‘ 0 ) = - π ∧ ( 𝑄𝑀 ) = π ) ∧ ∀ 𝑖 ∈ ( 0 ..^ 𝑀 ) ( 𝑄𝑖 ) < ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) )
245 15 fourierdlem2 ( 𝑀 ∈ ℕ → ( 𝑄 ∈ ( 𝑃𝑀 ) ↔ ( 𝑄 ∈ ( ℝ ↑m ( 0 ... 𝑀 ) ) ∧ ( ( ( 𝑄 ‘ 0 ) = - π ∧ ( 𝑄𝑀 ) = π ) ∧ ∀ 𝑖 ∈ ( 0 ..^ 𝑀 ) ( 𝑄𝑖 ) < ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) ) )
246 78 245 syl ( 𝜑 → ( 𝑄 ∈ ( 𝑃𝑀 ) ↔ ( 𝑄 ∈ ( ℝ ↑m ( 0 ... 𝑀 ) ) ∧ ( ( ( 𝑄 ‘ 0 ) = - π ∧ ( 𝑄𝑀 ) = π ) ∧ ∀ 𝑖 ∈ ( 0 ..^ 𝑀 ) ( 𝑄𝑖 ) < ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) ) )
247 108 244 246 mpbir2and ( 𝜑𝑄 ∈ ( 𝑃𝑀 ) )
248 4 reseq1i ( 𝐺 ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) = ( ( ( ℝ D 𝐹 ) ↾ ( - π (,) π ) ) ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) )
249 26 a1i ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → - π ∈ ℝ* )
250 27 a1i ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → π ∈ ℝ* )
251 186 adantr ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → 𝑄 : ( 0 ... 𝑀 ) ⟶ ( - π [,] π ) )
252 simpr ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → 𝑖 ∈ ( 0 ..^ 𝑀 ) )
253 249 250 251 252 fourierdlem27 ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ⊆ ( - π (,) π ) )
254 253 resabs1d ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( ( ℝ D 𝐹 ) ↾ ( - π (,) π ) ) ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) = ( ( ℝ D 𝐹 ) ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) )
255 248 254 syl5req ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( ℝ D 𝐹 ) ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) = ( 𝐺 ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) )
256 6 15 78 247 17 174 fourierdlem38 ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( 𝐺 ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) ∈ ( ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) –cn→ ℂ ) )
257 255 256 eqeltrd ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( ℝ D 𝐹 ) ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) ∈ ( ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) –cn→ ℂ ) )
258 255 oveq1d ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( ( ℝ D 𝐹 ) ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄𝑖 ) ) = ( ( 𝐺 ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄𝑖 ) ) )
259 6 adantr ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → 𝐺 ∈ ( dom 𝐺cn→ ℂ ) )
260 7 adantlr ( ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) ∧ 𝑥 ∈ ( ( - π [,) π ) ∖ dom 𝐺 ) ) → ( ( 𝐺 ↾ ( 𝑥 (,) +∞ ) ) lim 𝑥 ) ≠ ∅ )
261 8 adantlr ( ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) ∧ 𝑥 ∈ ( ( - π (,] π ) ∖ dom 𝐺 ) ) → ( ( 𝐺 ↾ ( -∞ (,) 𝑥 ) ) lim 𝑥 ) ≠ ∅ )
262 100 adantr ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → 𝑄 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) )
263 262 101 102 3syl ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → 𝑄 : ( 0 ... 𝑀 ) ⟶ 𝐻 )
264 89 adantr ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( 𝐸𝑋 ) ∈ ℝ )
265 262 172 173 3syl ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ran 𝑄 = 𝐻 )
266 259 260 261 262 263 252 242 253 264 17 265 fourierdlem46 ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( ( 𝐺 ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄𝑖 ) ) ≠ ∅ ∧ ( ( 𝐺 ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ≠ ∅ ) )
267 266 simpld ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( 𝐺 ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄𝑖 ) ) ≠ ∅ )
268 258 267 eqnetrd ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( ( ℝ D 𝐹 ) ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄𝑖 ) ) ≠ ∅ )
269 255 oveq1d ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( ( ℝ D 𝐹 ) ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) = ( ( 𝐺 ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) )
270 266 simprd ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( 𝐺 ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ≠ ∅ )
271 269 270 eqnetrd ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( ( ℝ D 𝐹 ) ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ≠ ∅ )
272 91 tpid3 ( 𝐸𝑋 ) ∈ { - π , π , ( 𝐸𝑋 ) }
273 elun1 ( ( 𝐸𝑋 ) ∈ { - π , π , ( 𝐸𝑋 ) } → ( 𝐸𝑋 ) ∈ ( { - π , π , ( 𝐸𝑋 ) } ∪ ( ( - π [,] π ) ∖ dom 𝐺 ) ) )
274 272 273 mp1i ( 𝜑 → ( 𝐸𝑋 ) ∈ ( { - π , π , ( 𝐸𝑋 ) } ∪ ( ( - π [,] π ) ∖ dom 𝐺 ) ) )
275 274 17 eleqtrrdi ( 𝜑 → ( 𝐸𝑋 ) ∈ 𝐻 )
276 275 174 eleqtrrd ( 𝜑 → ( 𝐸𝑋 ) ∈ ran 𝑄 )
277 1 2 3 9 10 11 15 78 247 257 268 271 12 13 14 16 276 fourierdlem113 ( 𝜑 → ( seq 1 ( + , 𝑆 ) ⇝ ( ( ( 𝐿 + 𝑅 ) / 2 ) − ( ( 𝐴 ‘ 0 ) / 2 ) ) ∧ ( ( ( 𝐴 ‘ 0 ) / 2 ) + Σ 𝑛 ∈ ℕ ( ( ( 𝐴𝑛 ) · ( cos ‘ ( 𝑛 · 𝑋 ) ) ) + ( ( 𝐵𝑛 ) · ( sin ‘ ( 𝑛 · 𝑋 ) ) ) ) ) = ( ( 𝐿 + 𝑅 ) / 2 ) ) )