Metamath Proof Explorer


Theorem fourierdlem102

Description: For a piecewise smooth function, the left and the right limits exist at any point. (Contributed by Glauco Siliprandi, 11-Dec-2019)

Ref Expression
Hypotheses fourierdlem102.f ( 𝜑𝐹 : ℝ ⟶ ℝ )
fourierdlem102.t 𝑇 = ( 2 · π )
fourierdlem102.per ( ( 𝜑𝑥 ∈ ℝ ) → ( 𝐹 ‘ ( 𝑥 + 𝑇 ) ) = ( 𝐹𝑥 ) )
fourierdlem102.g 𝐺 = ( ( ℝ D 𝐹 ) ↾ ( - π (,) π ) )
fourierdlem102.dmdv ( 𝜑 → ( ( - π (,) π ) ∖ dom 𝐺 ) ∈ Fin )
fourierdlem102.gcn ( 𝜑𝐺 ∈ ( dom 𝐺cn→ ℂ ) )
fourierdlem102.rlim ( ( 𝜑𝑥 ∈ ( ( - π [,) π ) ∖ dom 𝐺 ) ) → ( ( 𝐺 ↾ ( 𝑥 (,) +∞ ) ) lim 𝑥 ) ≠ ∅ )
fourierdlem102.llim ( ( 𝜑𝑥 ∈ ( ( - π (,] π ) ∖ dom 𝐺 ) ) → ( ( 𝐺 ↾ ( -∞ (,) 𝑥 ) ) lim 𝑥 ) ≠ ∅ )
fourierdlem102.x ( 𝜑𝑋 ∈ ℝ )
fourierdlem102.p 𝑃 = ( 𝑛 ∈ ℕ ↦ { 𝑝 ∈ ( ℝ ↑m ( 0 ... 𝑛 ) ) ∣ ( ( ( 𝑝 ‘ 0 ) = - π ∧ ( 𝑝𝑛 ) = π ) ∧ ∀ 𝑖 ∈ ( 0 ..^ 𝑛 ) ( 𝑝𝑖 ) < ( 𝑝 ‘ ( 𝑖 + 1 ) ) ) } )
fourierdlem102.e 𝐸 = ( 𝑥 ∈ ℝ ↦ ( 𝑥 + ( ( ⌊ ‘ ( ( π − 𝑥 ) / 𝑇 ) ) · 𝑇 ) ) )
fourierdlem102.h 𝐻 = ( { - π , π , ( 𝐸𝑋 ) } ∪ ( ( - π [,] π ) ∖ dom 𝐺 ) )
fourierdlem102.m 𝑀 = ( ( ♯ ‘ 𝐻 ) − 1 )
fourierdlem102.q 𝑄 = ( ℩ 𝑔 𝑔 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) )
Assertion fourierdlem102 ( 𝜑 → ( ( ( 𝐹 ↾ ( -∞ (,) 𝑋 ) ) lim 𝑋 ) ≠ ∅ ∧ ( ( 𝐹 ↾ ( 𝑋 (,) +∞ ) ) lim 𝑋 ) ≠ ∅ ) )

Proof

Step Hyp Ref Expression
1 fourierdlem102.f ( 𝜑𝐹 : ℝ ⟶ ℝ )
2 fourierdlem102.t 𝑇 = ( 2 · π )
3 fourierdlem102.per ( ( 𝜑𝑥 ∈ ℝ ) → ( 𝐹 ‘ ( 𝑥 + 𝑇 ) ) = ( 𝐹𝑥 ) )
4 fourierdlem102.g 𝐺 = ( ( ℝ D 𝐹 ) ↾ ( - π (,) π ) )
5 fourierdlem102.dmdv ( 𝜑 → ( ( - π (,) π ) ∖ dom 𝐺 ) ∈ Fin )
6 fourierdlem102.gcn ( 𝜑𝐺 ∈ ( dom 𝐺cn→ ℂ ) )
7 fourierdlem102.rlim ( ( 𝜑𝑥 ∈ ( ( - π [,) π ) ∖ dom 𝐺 ) ) → ( ( 𝐺 ↾ ( 𝑥 (,) +∞ ) ) lim 𝑥 ) ≠ ∅ )
8 fourierdlem102.llim ( ( 𝜑𝑥 ∈ ( ( - π (,] π ) ∖ dom 𝐺 ) ) → ( ( 𝐺 ↾ ( -∞ (,) 𝑥 ) ) lim 𝑥 ) ≠ ∅ )
9 fourierdlem102.x ( 𝜑𝑋 ∈ ℝ )
10 fourierdlem102.p 𝑃 = ( 𝑛 ∈ ℕ ↦ { 𝑝 ∈ ( ℝ ↑m ( 0 ... 𝑛 ) ) ∣ ( ( ( 𝑝 ‘ 0 ) = - π ∧ ( 𝑝𝑛 ) = π ) ∧ ∀ 𝑖 ∈ ( 0 ..^ 𝑛 ) ( 𝑝𝑖 ) < ( 𝑝 ‘ ( 𝑖 + 1 ) ) ) } )
11 fourierdlem102.e 𝐸 = ( 𝑥 ∈ ℝ ↦ ( 𝑥 + ( ( ⌊ ‘ ( ( π − 𝑥 ) / 𝑇 ) ) · 𝑇 ) ) )
12 fourierdlem102.h 𝐻 = ( { - π , π , ( 𝐸𝑋 ) } ∪ ( ( - π [,] π ) ∖ dom 𝐺 ) )
13 fourierdlem102.m 𝑀 = ( ( ♯ ‘ 𝐻 ) − 1 )
14 fourierdlem102.q 𝑄 = ( ℩ 𝑔 𝑔 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) )
15 2z 2 ∈ ℤ
16 15 a1i ( 𝜑 → 2 ∈ ℤ )
17 tpfi { - π , π , ( 𝐸𝑋 ) } ∈ Fin
18 17 a1i ( 𝜑 → { - π , π , ( 𝐸𝑋 ) } ∈ Fin )
19 pire π ∈ ℝ
20 19 renegcli - π ∈ ℝ
21 20 rexri - π ∈ ℝ*
22 19 rexri π ∈ ℝ*
23 negpilt0 - π < 0
24 pipos 0 < π
25 0re 0 ∈ ℝ
26 20 25 19 lttri ( ( - π < 0 ∧ 0 < π ) → - π < π )
27 23 24 26 mp2an - π < π
28 20 19 27 ltleii - π ≤ π
29 prunioo ( ( - π ∈ ℝ* ∧ π ∈ ℝ* ∧ - π ≤ π ) → ( ( - π (,) π ) ∪ { - π , π } ) = ( - π [,] π ) )
30 21 22 28 29 mp3an ( ( - π (,) π ) ∪ { - π , π } ) = ( - π [,] π )
31 30 difeq1i ( ( ( - π (,) π ) ∪ { - π , π } ) ∖ dom 𝐺 ) = ( ( - π [,] π ) ∖ dom 𝐺 )
32 difundir ( ( ( - π (,) π ) ∪ { - π , π } ) ∖ dom 𝐺 ) = ( ( ( - π (,) π ) ∖ dom 𝐺 ) ∪ ( { - π , π } ∖ dom 𝐺 ) )
33 31 32 eqtr3i ( ( - π [,] π ) ∖ dom 𝐺 ) = ( ( ( - π (,) π ) ∖ dom 𝐺 ) ∪ ( { - π , π } ∖ dom 𝐺 ) )
34 prfi { - π , π } ∈ Fin
35 diffi ( { - π , π } ∈ Fin → ( { - π , π } ∖ dom 𝐺 ) ∈ Fin )
36 34 35 mp1i ( 𝜑 → ( { - π , π } ∖ dom 𝐺 ) ∈ Fin )
37 unfi ( ( ( ( - π (,) π ) ∖ dom 𝐺 ) ∈ Fin ∧ ( { - π , π } ∖ dom 𝐺 ) ∈ Fin ) → ( ( ( - π (,) π ) ∖ dom 𝐺 ) ∪ ( { - π , π } ∖ dom 𝐺 ) ) ∈ Fin )
38 5 36 37 syl2anc ( 𝜑 → ( ( ( - π (,) π ) ∖ dom 𝐺 ) ∪ ( { - π , π } ∖ dom 𝐺 ) ) ∈ Fin )
39 33 38 eqeltrid ( 𝜑 → ( ( - π [,] π ) ∖ dom 𝐺 ) ∈ Fin )
40 unfi ( ( { - π , π , ( 𝐸𝑋 ) } ∈ Fin ∧ ( ( - π [,] π ) ∖ dom 𝐺 ) ∈ Fin ) → ( { - π , π , ( 𝐸𝑋 ) } ∪ ( ( - π [,] π ) ∖ dom 𝐺 ) ) ∈ Fin )
41 18 39 40 syl2anc ( 𝜑 → ( { - π , π , ( 𝐸𝑋 ) } ∪ ( ( - π [,] π ) ∖ dom 𝐺 ) ) ∈ Fin )
42 12 41 eqeltrid ( 𝜑𝐻 ∈ Fin )
43 hashcl ( 𝐻 ∈ Fin → ( ♯ ‘ 𝐻 ) ∈ ℕ0 )
44 42 43 syl ( 𝜑 → ( ♯ ‘ 𝐻 ) ∈ ℕ0 )
45 44 nn0zd ( 𝜑 → ( ♯ ‘ 𝐻 ) ∈ ℤ )
46 20 27 ltneii - π ≠ π
47 hashprg ( ( - π ∈ ℝ ∧ π ∈ ℝ ) → ( - π ≠ π ↔ ( ♯ ‘ { - π , π } ) = 2 ) )
48 20 19 47 mp2an ( - π ≠ π ↔ ( ♯ ‘ { - π , π } ) = 2 )
49 46 48 mpbi ( ♯ ‘ { - π , π } ) = 2
50 17 elexi { - π , π , ( 𝐸𝑋 ) } ∈ V
51 ovex ( - π [,] π ) ∈ V
52 difexg ( ( - π [,] π ) ∈ V → ( ( - π [,] π ) ∖ dom 𝐺 ) ∈ V )
53 51 52 ax-mp ( ( - π [,] π ) ∖ dom 𝐺 ) ∈ V
54 50 53 unex ( { - π , π , ( 𝐸𝑋 ) } ∪ ( ( - π [,] π ) ∖ dom 𝐺 ) ) ∈ V
55 12 54 eqeltri 𝐻 ∈ V
56 negex - π ∈ V
57 56 tpid1 - π ∈ { - π , π , ( 𝐸𝑋 ) }
58 19 elexi π ∈ V
59 58 tpid2 π ∈ { - π , π , ( 𝐸𝑋 ) }
60 prssi ( ( - π ∈ { - π , π , ( 𝐸𝑋 ) } ∧ π ∈ { - π , π , ( 𝐸𝑋 ) } ) → { - π , π } ⊆ { - π , π , ( 𝐸𝑋 ) } )
61 57 59 60 mp2an { - π , π } ⊆ { - π , π , ( 𝐸𝑋 ) }
62 ssun1 { - π , π , ( 𝐸𝑋 ) } ⊆ ( { - π , π , ( 𝐸𝑋 ) } ∪ ( ( - π [,] π ) ∖ dom 𝐺 ) )
63 62 12 sseqtrri { - π , π , ( 𝐸𝑋 ) } ⊆ 𝐻
64 61 63 sstri { - π , π } ⊆ 𝐻
65 hashss ( ( 𝐻 ∈ V ∧ { - π , π } ⊆ 𝐻 ) → ( ♯ ‘ { - π , π } ) ≤ ( ♯ ‘ 𝐻 ) )
66 55 64 65 mp2an ( ♯ ‘ { - π , π } ) ≤ ( ♯ ‘ 𝐻 )
67 66 a1i ( 𝜑 → ( ♯ ‘ { - π , π } ) ≤ ( ♯ ‘ 𝐻 ) )
68 49 67 eqbrtrrid ( 𝜑 → 2 ≤ ( ♯ ‘ 𝐻 ) )
69 eluz2 ( ( ♯ ‘ 𝐻 ) ∈ ( ℤ ‘ 2 ) ↔ ( 2 ∈ ℤ ∧ ( ♯ ‘ 𝐻 ) ∈ ℤ ∧ 2 ≤ ( ♯ ‘ 𝐻 ) ) )
70 16 45 68 69 syl3anbrc ( 𝜑 → ( ♯ ‘ 𝐻 ) ∈ ( ℤ ‘ 2 ) )
71 uz2m1nn ( ( ♯ ‘ 𝐻 ) ∈ ( ℤ ‘ 2 ) → ( ( ♯ ‘ 𝐻 ) − 1 ) ∈ ℕ )
72 70 71 syl ( 𝜑 → ( ( ♯ ‘ 𝐻 ) − 1 ) ∈ ℕ )
73 13 72 eqeltrid ( 𝜑𝑀 ∈ ℕ )
74 20 a1i ( 𝜑 → - π ∈ ℝ )
75 19 a1i ( 𝜑 → π ∈ ℝ )
76 negpitopissre ( - π (,] π ) ⊆ ℝ
77 27 a1i ( 𝜑 → - π < π )
78 picn π ∈ ℂ
79 78 2timesi ( 2 · π ) = ( π + π )
80 78 78 subnegi ( π − - π ) = ( π + π )
81 79 2 80 3eqtr4i 𝑇 = ( π − - π )
82 74 75 77 81 11 fourierdlem4 ( 𝜑𝐸 : ℝ ⟶ ( - π (,] π ) )
83 82 9 ffvelrnd ( 𝜑 → ( 𝐸𝑋 ) ∈ ( - π (,] π ) )
84 76 83 sseldi ( 𝜑 → ( 𝐸𝑋 ) ∈ ℝ )
85 74 75 84 3jca ( 𝜑 → ( - π ∈ ℝ ∧ π ∈ ℝ ∧ ( 𝐸𝑋 ) ∈ ℝ ) )
86 fvex ( 𝐸𝑋 ) ∈ V
87 56 58 86 tpss ( ( - π ∈ ℝ ∧ π ∈ ℝ ∧ ( 𝐸𝑋 ) ∈ ℝ ) ↔ { - π , π , ( 𝐸𝑋 ) } ⊆ ℝ )
88 85 87 sylib ( 𝜑 → { - π , π , ( 𝐸𝑋 ) } ⊆ ℝ )
89 iccssre ( ( - π ∈ ℝ ∧ π ∈ ℝ ) → ( - π [,] π ) ⊆ ℝ )
90 20 19 89 mp2an ( - π [,] π ) ⊆ ℝ
91 ssdifss ( ( - π [,] π ) ⊆ ℝ → ( ( - π [,] π ) ∖ dom 𝐺 ) ⊆ ℝ )
92 90 91 mp1i ( 𝜑 → ( ( - π [,] π ) ∖ dom 𝐺 ) ⊆ ℝ )
93 88 92 unssd ( 𝜑 → ( { - π , π , ( 𝐸𝑋 ) } ∪ ( ( - π [,] π ) ∖ dom 𝐺 ) ) ⊆ ℝ )
94 12 93 eqsstrid ( 𝜑𝐻 ⊆ ℝ )
95 42 94 14 13 fourierdlem36 ( 𝜑𝑄 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) )
96 isof1o ( 𝑄 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) → 𝑄 : ( 0 ... 𝑀 ) –1-1-onto𝐻 )
97 f1of ( 𝑄 : ( 0 ... 𝑀 ) –1-1-onto𝐻𝑄 : ( 0 ... 𝑀 ) ⟶ 𝐻 )
98 95 96 97 3syl ( 𝜑𝑄 : ( 0 ... 𝑀 ) ⟶ 𝐻 )
99 98 94 fssd ( 𝜑𝑄 : ( 0 ... 𝑀 ) ⟶ ℝ )
100 reex ℝ ∈ V
101 ovex ( 0 ... 𝑀 ) ∈ V
102 100 101 elmap ( 𝑄 ∈ ( ℝ ↑m ( 0 ... 𝑀 ) ) ↔ 𝑄 : ( 0 ... 𝑀 ) ⟶ ℝ )
103 99 102 sylibr ( 𝜑𝑄 ∈ ( ℝ ↑m ( 0 ... 𝑀 ) ) )
104 fveq2 ( 0 = 𝑖 → ( 𝑄 ‘ 0 ) = ( 𝑄𝑖 ) )
105 104 adantl ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 = 𝑖 ) → ( 𝑄 ‘ 0 ) = ( 𝑄𝑖 ) )
106 99 ffvelrnda ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) → ( 𝑄𝑖 ) ∈ ℝ )
107 106 leidd ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) → ( 𝑄𝑖 ) ≤ ( 𝑄𝑖 ) )
108 107 adantr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 = 𝑖 ) → ( 𝑄𝑖 ) ≤ ( 𝑄𝑖 ) )
109 105 108 eqbrtrd ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 = 𝑖 ) → ( 𝑄 ‘ 0 ) ≤ ( 𝑄𝑖 ) )
110 elfzelz ( 𝑖 ∈ ( 0 ... 𝑀 ) → 𝑖 ∈ ℤ )
111 110 zred ( 𝑖 ∈ ( 0 ... 𝑀 ) → 𝑖 ∈ ℝ )
112 111 ad2antlr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 0 = 𝑖 ) → 𝑖 ∈ ℝ )
113 elfzle1 ( 𝑖 ∈ ( 0 ... 𝑀 ) → 0 ≤ 𝑖 )
114 113 ad2antlr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 0 = 𝑖 ) → 0 ≤ 𝑖 )
115 neqne ( ¬ 0 = 𝑖 → 0 ≠ 𝑖 )
116 115 necomd ( ¬ 0 = 𝑖𝑖 ≠ 0 )
117 116 adantl ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 0 = 𝑖 ) → 𝑖 ≠ 0 )
118 112 114 117 ne0gt0d ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 0 = 𝑖 ) → 0 < 𝑖 )
119 nnssnn0 ℕ ⊆ ℕ0
120 nn0uz 0 = ( ℤ ‘ 0 )
121 119 120 sseqtri ℕ ⊆ ( ℤ ‘ 0 )
122 121 73 sseldi ( 𝜑𝑀 ∈ ( ℤ ‘ 0 ) )
123 eluzfz1 ( 𝑀 ∈ ( ℤ ‘ 0 ) → 0 ∈ ( 0 ... 𝑀 ) )
124 122 123 syl ( 𝜑 → 0 ∈ ( 0 ... 𝑀 ) )
125 98 124 ffvelrnd ( 𝜑 → ( 𝑄 ‘ 0 ) ∈ 𝐻 )
126 94 125 sseldd ( 𝜑 → ( 𝑄 ‘ 0 ) ∈ ℝ )
127 126 ad2antrr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 < 𝑖 ) → ( 𝑄 ‘ 0 ) ∈ ℝ )
128 106 adantr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 < 𝑖 ) → ( 𝑄𝑖 ) ∈ ℝ )
129 simpr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 < 𝑖 ) → 0 < 𝑖 )
130 95 ad2antrr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 < 𝑖 ) → 𝑄 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) )
131 124 anim1i ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) → ( 0 ∈ ( 0 ... 𝑀 ) ∧ 𝑖 ∈ ( 0 ... 𝑀 ) ) )
132 131 adantr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 < 𝑖 ) → ( 0 ∈ ( 0 ... 𝑀 ) ∧ 𝑖 ∈ ( 0 ... 𝑀 ) ) )
133 isorel ( ( 𝑄 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) ∧ ( 0 ∈ ( 0 ... 𝑀 ) ∧ 𝑖 ∈ ( 0 ... 𝑀 ) ) ) → ( 0 < 𝑖 ↔ ( 𝑄 ‘ 0 ) < ( 𝑄𝑖 ) ) )
134 130 132 133 syl2anc ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 < 𝑖 ) → ( 0 < 𝑖 ↔ ( 𝑄 ‘ 0 ) < ( 𝑄𝑖 ) ) )
135 129 134 mpbid ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 < 𝑖 ) → ( 𝑄 ‘ 0 ) < ( 𝑄𝑖 ) )
136 127 128 135 ltled ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 0 < 𝑖 ) → ( 𝑄 ‘ 0 ) ≤ ( 𝑄𝑖 ) )
137 118 136 syldan ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 0 = 𝑖 ) → ( 𝑄 ‘ 0 ) ≤ ( 𝑄𝑖 ) )
138 109 137 pm2.61dan ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) → ( 𝑄 ‘ 0 ) ≤ ( 𝑄𝑖 ) )
139 138 adantr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ( 𝑄𝑖 ) = - π ) → ( 𝑄 ‘ 0 ) ≤ ( 𝑄𝑖 ) )
140 simpr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ( 𝑄𝑖 ) = - π ) → ( 𝑄𝑖 ) = - π )
141 139 140 breqtrd ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ( 𝑄𝑖 ) = - π ) → ( 𝑄 ‘ 0 ) ≤ - π )
142 74 rexrd ( 𝜑 → - π ∈ ℝ* )
143 75 rexrd ( 𝜑 → π ∈ ℝ* )
144 lbicc2 ( ( - π ∈ ℝ* ∧ π ∈ ℝ* ∧ - π ≤ π ) → - π ∈ ( - π [,] π ) )
145 21 22 28 144 mp3an - π ∈ ( - π [,] π )
146 145 a1i ( 𝜑 → - π ∈ ( - π [,] π ) )
147 ubicc2 ( ( - π ∈ ℝ* ∧ π ∈ ℝ* ∧ - π ≤ π ) → π ∈ ( - π [,] π ) )
148 21 22 28 147 mp3an π ∈ ( - π [,] π )
149 148 a1i ( 𝜑 → π ∈ ( - π [,] π ) )
150 iocssicc ( - π (,] π ) ⊆ ( - π [,] π )
151 150 83 sseldi ( 𝜑 → ( 𝐸𝑋 ) ∈ ( - π [,] π ) )
152 tpssi ( ( - π ∈ ( - π [,] π ) ∧ π ∈ ( - π [,] π ) ∧ ( 𝐸𝑋 ) ∈ ( - π [,] π ) ) → { - π , π , ( 𝐸𝑋 ) } ⊆ ( - π [,] π ) )
153 146 149 151 152 syl3anc ( 𝜑 → { - π , π , ( 𝐸𝑋 ) } ⊆ ( - π [,] π ) )
154 difssd ( 𝜑 → ( ( - π [,] π ) ∖ dom 𝐺 ) ⊆ ( - π [,] π ) )
155 153 154 unssd ( 𝜑 → ( { - π , π , ( 𝐸𝑋 ) } ∪ ( ( - π [,] π ) ∖ dom 𝐺 ) ) ⊆ ( - π [,] π ) )
156 12 155 eqsstrid ( 𝜑𝐻 ⊆ ( - π [,] π ) )
157 156 125 sseldd ( 𝜑 → ( 𝑄 ‘ 0 ) ∈ ( - π [,] π ) )
158 iccgelb ( ( - π ∈ ℝ* ∧ π ∈ ℝ* ∧ ( 𝑄 ‘ 0 ) ∈ ( - π [,] π ) ) → - π ≤ ( 𝑄 ‘ 0 ) )
159 142 143 157 158 syl3anc ( 𝜑 → - π ≤ ( 𝑄 ‘ 0 ) )
160 159 ad2antrr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ( 𝑄𝑖 ) = - π ) → - π ≤ ( 𝑄 ‘ 0 ) )
161 126 ad2antrr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ( 𝑄𝑖 ) = - π ) → ( 𝑄 ‘ 0 ) ∈ ℝ )
162 20 a1i ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ( 𝑄𝑖 ) = - π ) → - π ∈ ℝ )
163 161 162 letri3d ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ( 𝑄𝑖 ) = - π ) → ( ( 𝑄 ‘ 0 ) = - π ↔ ( ( 𝑄 ‘ 0 ) ≤ - π ∧ - π ≤ ( 𝑄 ‘ 0 ) ) ) )
164 141 160 163 mpbir2and ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ( 𝑄𝑖 ) = - π ) → ( 𝑄 ‘ 0 ) = - π )
165 63 57 sselii - π ∈ 𝐻
166 f1ofo ( 𝑄 : ( 0 ... 𝑀 ) –1-1-onto𝐻𝑄 : ( 0 ... 𝑀 ) –onto𝐻 )
167 96 166 syl ( 𝑄 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) → 𝑄 : ( 0 ... 𝑀 ) –onto𝐻 )
168 forn ( 𝑄 : ( 0 ... 𝑀 ) –onto𝐻 → ran 𝑄 = 𝐻 )
169 95 167 168 3syl ( 𝜑 → ran 𝑄 = 𝐻 )
170 165 169 eleqtrrid ( 𝜑 → - π ∈ ran 𝑄 )
171 ffn ( 𝑄 : ( 0 ... 𝑀 ) ⟶ 𝐻𝑄 Fn ( 0 ... 𝑀 ) )
172 fvelrnb ( 𝑄 Fn ( 0 ... 𝑀 ) → ( - π ∈ ran 𝑄 ↔ ∃ 𝑖 ∈ ( 0 ... 𝑀 ) ( 𝑄𝑖 ) = - π ) )
173 98 171 172 3syl ( 𝜑 → ( - π ∈ ran 𝑄 ↔ ∃ 𝑖 ∈ ( 0 ... 𝑀 ) ( 𝑄𝑖 ) = - π ) )
174 170 173 mpbid ( 𝜑 → ∃ 𝑖 ∈ ( 0 ... 𝑀 ) ( 𝑄𝑖 ) = - π )
175 164 174 r19.29a ( 𝜑 → ( 𝑄 ‘ 0 ) = - π )
176 63 59 sselii π ∈ 𝐻
177 176 169 eleqtrrid ( 𝜑 → π ∈ ran 𝑄 )
178 fvelrnb ( 𝑄 Fn ( 0 ... 𝑀 ) → ( π ∈ ran 𝑄 ↔ ∃ 𝑖 ∈ ( 0 ... 𝑀 ) ( 𝑄𝑖 ) = π ) )
179 98 171 178 3syl ( 𝜑 → ( π ∈ ran 𝑄 ↔ ∃ 𝑖 ∈ ( 0 ... 𝑀 ) ( 𝑄𝑖 ) = π ) )
180 177 179 mpbid ( 𝜑 → ∃ 𝑖 ∈ ( 0 ... 𝑀 ) ( 𝑄𝑖 ) = π )
181 98 156 fssd ( 𝜑𝑄 : ( 0 ... 𝑀 ) ⟶ ( - π [,] π ) )
182 eluzfz2 ( 𝑀 ∈ ( ℤ ‘ 0 ) → 𝑀 ∈ ( 0 ... 𝑀 ) )
183 122 182 syl ( 𝜑𝑀 ∈ ( 0 ... 𝑀 ) )
184 181 183 ffvelrnd ( 𝜑 → ( 𝑄𝑀 ) ∈ ( - π [,] π ) )
185 iccleub ( ( - π ∈ ℝ* ∧ π ∈ ℝ* ∧ ( 𝑄𝑀 ) ∈ ( - π [,] π ) ) → ( 𝑄𝑀 ) ≤ π )
186 142 143 184 185 syl3anc ( 𝜑 → ( 𝑄𝑀 ) ≤ π )
187 186 3ad2ant1 ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑄𝑖 ) = π ) → ( 𝑄𝑀 ) ≤ π )
188 id ( ( 𝑄𝑖 ) = π → ( 𝑄𝑖 ) = π )
189 188 eqcomd ( ( 𝑄𝑖 ) = π → π = ( 𝑄𝑖 ) )
190 189 3ad2ant3 ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑄𝑖 ) = π ) → π = ( 𝑄𝑖 ) )
191 107 adantr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 = 𝑀 ) → ( 𝑄𝑖 ) ≤ ( 𝑄𝑖 ) )
192 fveq2 ( 𝑖 = 𝑀 → ( 𝑄𝑖 ) = ( 𝑄𝑀 ) )
193 192 adantl ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 = 𝑀 ) → ( 𝑄𝑖 ) = ( 𝑄𝑀 ) )
194 191 193 breqtrd ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 = 𝑀 ) → ( 𝑄𝑖 ) ≤ ( 𝑄𝑀 ) )
195 111 ad2antlr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 𝑖 = 𝑀 ) → 𝑖 ∈ ℝ )
196 elfzel2 ( 𝑖 ∈ ( 0 ... 𝑀 ) → 𝑀 ∈ ℤ )
197 196 zred ( 𝑖 ∈ ( 0 ... 𝑀 ) → 𝑀 ∈ ℝ )
198 197 ad2antlr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 𝑖 = 𝑀 ) → 𝑀 ∈ ℝ )
199 elfzle2 ( 𝑖 ∈ ( 0 ... 𝑀 ) → 𝑖𝑀 )
200 199 ad2antlr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 𝑖 = 𝑀 ) → 𝑖𝑀 )
201 neqne ( ¬ 𝑖 = 𝑀𝑖𝑀 )
202 201 necomd ( ¬ 𝑖 = 𝑀𝑀𝑖 )
203 202 adantl ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 𝑖 = 𝑀 ) → 𝑀𝑖 )
204 195 198 200 203 leneltd ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 𝑖 = 𝑀 ) → 𝑖 < 𝑀 )
205 106 adantr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 < 𝑀 ) → ( 𝑄𝑖 ) ∈ ℝ )
206 90 184 sseldi ( 𝜑 → ( 𝑄𝑀 ) ∈ ℝ )
207 206 ad2antrr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 < 𝑀 ) → ( 𝑄𝑀 ) ∈ ℝ )
208 simpr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 < 𝑀 ) → 𝑖 < 𝑀 )
209 95 ad2antrr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 < 𝑀 ) → 𝑄 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) )
210 simpr ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) → 𝑖 ∈ ( 0 ... 𝑀 ) )
211 183 adantr ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) → 𝑀 ∈ ( 0 ... 𝑀 ) )
212 210 211 jca ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) → ( 𝑖 ∈ ( 0 ... 𝑀 ) ∧ 𝑀 ∈ ( 0 ... 𝑀 ) ) )
213 212 adantr ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 < 𝑀 ) → ( 𝑖 ∈ ( 0 ... 𝑀 ) ∧ 𝑀 ∈ ( 0 ... 𝑀 ) ) )
214 isorel ( ( 𝑄 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) ∧ ( 𝑖 ∈ ( 0 ... 𝑀 ) ∧ 𝑀 ∈ ( 0 ... 𝑀 ) ) ) → ( 𝑖 < 𝑀 ↔ ( 𝑄𝑖 ) < ( 𝑄𝑀 ) ) )
215 209 213 214 syl2anc ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 < 𝑀 ) → ( 𝑖 < 𝑀 ↔ ( 𝑄𝑖 ) < ( 𝑄𝑀 ) ) )
216 208 215 mpbid ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 < 𝑀 ) → ( 𝑄𝑖 ) < ( 𝑄𝑀 ) )
217 205 207 216 ltled ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ 𝑖 < 𝑀 ) → ( 𝑄𝑖 ) ≤ ( 𝑄𝑀 ) )
218 204 217 syldan ( ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) ∧ ¬ 𝑖 = 𝑀 ) → ( 𝑄𝑖 ) ≤ ( 𝑄𝑀 ) )
219 194 218 pm2.61dan ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ) → ( 𝑄𝑖 ) ≤ ( 𝑄𝑀 ) )
220 219 3adant3 ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑄𝑖 ) = π ) → ( 𝑄𝑖 ) ≤ ( 𝑄𝑀 ) )
221 190 220 eqbrtrd ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑄𝑖 ) = π ) → π ≤ ( 𝑄𝑀 ) )
222 206 3ad2ant1 ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑄𝑖 ) = π ) → ( 𝑄𝑀 ) ∈ ℝ )
223 19 a1i ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑄𝑖 ) = π ) → π ∈ ℝ )
224 222 223 letri3d ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑄𝑖 ) = π ) → ( ( 𝑄𝑀 ) = π ↔ ( ( 𝑄𝑀 ) ≤ π ∧ π ≤ ( 𝑄𝑀 ) ) ) )
225 187 221 224 mpbir2and ( ( 𝜑𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑄𝑖 ) = π ) → ( 𝑄𝑀 ) = π )
226 225 rexlimdv3a ( 𝜑 → ( ∃ 𝑖 ∈ ( 0 ... 𝑀 ) ( 𝑄𝑖 ) = π → ( 𝑄𝑀 ) = π ) )
227 180 226 mpd ( 𝜑 → ( 𝑄𝑀 ) = π )
228 elfzoelz ( 𝑖 ∈ ( 0 ..^ 𝑀 ) → 𝑖 ∈ ℤ )
229 228 zred ( 𝑖 ∈ ( 0 ..^ 𝑀 ) → 𝑖 ∈ ℝ )
230 229 ltp1d ( 𝑖 ∈ ( 0 ..^ 𝑀 ) → 𝑖 < ( 𝑖 + 1 ) )
231 230 adantl ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → 𝑖 < ( 𝑖 + 1 ) )
232 elfzofz ( 𝑖 ∈ ( 0 ..^ 𝑀 ) → 𝑖 ∈ ( 0 ... 𝑀 ) )
233 fzofzp1 ( 𝑖 ∈ ( 0 ..^ 𝑀 ) → ( 𝑖 + 1 ) ∈ ( 0 ... 𝑀 ) )
234 232 233 jca ( 𝑖 ∈ ( 0 ..^ 𝑀 ) → ( 𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑖 + 1 ) ∈ ( 0 ... 𝑀 ) ) )
235 isorel ( ( 𝑄 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) ∧ ( 𝑖 ∈ ( 0 ... 𝑀 ) ∧ ( 𝑖 + 1 ) ∈ ( 0 ... 𝑀 ) ) ) → ( 𝑖 < ( 𝑖 + 1 ) ↔ ( 𝑄𝑖 ) < ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) )
236 95 234 235 syl2an ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( 𝑖 < ( 𝑖 + 1 ) ↔ ( 𝑄𝑖 ) < ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) )
237 231 236 mpbid ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( 𝑄𝑖 ) < ( 𝑄 ‘ ( 𝑖 + 1 ) ) )
238 237 ralrimiva ( 𝜑 → ∀ 𝑖 ∈ ( 0 ..^ 𝑀 ) ( 𝑄𝑖 ) < ( 𝑄 ‘ ( 𝑖 + 1 ) ) )
239 175 227 238 jca31 ( 𝜑 → ( ( ( 𝑄 ‘ 0 ) = - π ∧ ( 𝑄𝑀 ) = π ) ∧ ∀ 𝑖 ∈ ( 0 ..^ 𝑀 ) ( 𝑄𝑖 ) < ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) )
240 10 fourierdlem2 ( 𝑀 ∈ ℕ → ( 𝑄 ∈ ( 𝑃𝑀 ) ↔ ( 𝑄 ∈ ( ℝ ↑m ( 0 ... 𝑀 ) ) ∧ ( ( ( 𝑄 ‘ 0 ) = - π ∧ ( 𝑄𝑀 ) = π ) ∧ ∀ 𝑖 ∈ ( 0 ..^ 𝑀 ) ( 𝑄𝑖 ) < ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) ) )
241 73 240 syl ( 𝜑 → ( 𝑄 ∈ ( 𝑃𝑀 ) ↔ ( 𝑄 ∈ ( ℝ ↑m ( 0 ... 𝑀 ) ) ∧ ( ( ( 𝑄 ‘ 0 ) = - π ∧ ( 𝑄𝑀 ) = π ) ∧ ∀ 𝑖 ∈ ( 0 ..^ 𝑀 ) ( 𝑄𝑖 ) < ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) ) )
242 103 239 241 mpbir2and ( 𝜑𝑄 ∈ ( 𝑃𝑀 ) )
243 4 reseq1i ( 𝐺 ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) = ( ( ( ℝ D 𝐹 ) ↾ ( - π (,) π ) ) ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) )
244 21 a1i ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → - π ∈ ℝ* )
245 22 a1i ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → π ∈ ℝ* )
246 181 adantr ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → 𝑄 : ( 0 ... 𝑀 ) ⟶ ( - π [,] π ) )
247 simpr ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → 𝑖 ∈ ( 0 ..^ 𝑀 ) )
248 244 245 246 247 fourierdlem27 ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ⊆ ( - π (,) π ) )
249 248 resabs1d ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( ( ℝ D 𝐹 ) ↾ ( - π (,) π ) ) ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) = ( ( ℝ D 𝐹 ) ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) )
250 243 249 syl5req ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( ℝ D 𝐹 ) ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) = ( 𝐺 ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) )
251 6 10 73 242 12 169 fourierdlem38 ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( 𝐺 ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) ∈ ( ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) –cn→ ℂ ) )
252 250 251 eqeltrd ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( ℝ D 𝐹 ) ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) ∈ ( ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) –cn→ ℂ ) )
253 250 oveq1d ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( ( ℝ D 𝐹 ) ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄𝑖 ) ) = ( ( 𝐺 ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄𝑖 ) ) )
254 6 adantr ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → 𝐺 ∈ ( dom 𝐺cn→ ℂ ) )
255 7 adantlr ( ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) ∧ 𝑥 ∈ ( ( - π [,) π ) ∖ dom 𝐺 ) ) → ( ( 𝐺 ↾ ( 𝑥 (,) +∞ ) ) lim 𝑥 ) ≠ ∅ )
256 8 adantlr ( ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) ∧ 𝑥 ∈ ( ( - π (,] π ) ∖ dom 𝐺 ) ) → ( ( 𝐺 ↾ ( -∞ (,) 𝑥 ) ) lim 𝑥 ) ≠ ∅ )
257 95 adantr ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → 𝑄 Isom < , < ( ( 0 ... 𝑀 ) , 𝐻 ) )
258 257 96 97 3syl ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → 𝑄 : ( 0 ... 𝑀 ) ⟶ 𝐻 )
259 84 adantr ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( 𝐸𝑋 ) ∈ ℝ )
260 257 167 168 3syl ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ran 𝑄 = 𝐻 )
261 254 255 256 257 258 247 237 248 259 12 260 fourierdlem46 ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( ( 𝐺 ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄𝑖 ) ) ≠ ∅ ∧ ( ( 𝐺 ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ≠ ∅ ) )
262 261 simpld ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( 𝐺 ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄𝑖 ) ) ≠ ∅ )
263 253 262 eqnetrd ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( ( ℝ D 𝐹 ) ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄𝑖 ) ) ≠ ∅ )
264 250 oveq1d ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( ( ℝ D 𝐹 ) ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) = ( ( 𝐺 ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) )
265 261 simprd ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( 𝐺 ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ≠ ∅ )
266 264 265 eqnetrd ( ( 𝜑𝑖 ∈ ( 0 ..^ 𝑀 ) ) → ( ( ( ℝ D 𝐹 ) ↾ ( ( 𝑄𝑖 ) (,) ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ) lim ( 𝑄 ‘ ( 𝑖 + 1 ) ) ) ≠ ∅ )
267 1 2 3 9 10 73 242 252 263 266 fourierdlem94 ( 𝜑 → ( ( ( 𝐹 ↾ ( -∞ (,) 𝑋 ) ) lim 𝑋 ) ≠ ∅ ∧ ( ( 𝐹 ↾ ( 𝑋 (,) +∞ ) ) lim 𝑋 ) ≠ ∅ ) )