Metamath Proof Explorer


Theorem taylply2

Description: The Taylor polynomial is a polynomial of degree (at most) N . This version of taylply shows that the coefficients of T are in a subring of the complex numbers. (Contributed by Mario Carneiro, 1-Jan-2017)

Ref Expression
Hypotheses taylpfval.s ( 𝜑𝑆 ∈ { ℝ , ℂ } )
taylpfval.f ( 𝜑𝐹 : 𝐴 ⟶ ℂ )
taylpfval.a ( 𝜑𝐴𝑆 )
taylpfval.n ( 𝜑𝑁 ∈ ℕ0 )
taylpfval.b ( 𝜑𝐵 ∈ dom ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑁 ) )
taylpfval.t 𝑇 = ( 𝑁 ( 𝑆 Tayl 𝐹 ) 𝐵 )
taylply2.1 ( 𝜑𝐷 ∈ ( SubRing ‘ ℂfld ) )
taylply2.2 ( 𝜑𝐵𝐷 )
taylply2.3 ( ( 𝜑𝑘 ∈ ( 0 ... 𝑁 ) ) → ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) ∈ 𝐷 )
Assertion taylply2 ( 𝜑 → ( 𝑇 ∈ ( Poly ‘ 𝐷 ) ∧ ( deg ‘ 𝑇 ) ≤ 𝑁 ) )

Proof

Step Hyp Ref Expression
1 taylpfval.s ( 𝜑𝑆 ∈ { ℝ , ℂ } )
2 taylpfval.f ( 𝜑𝐹 : 𝐴 ⟶ ℂ )
3 taylpfval.a ( 𝜑𝐴𝑆 )
4 taylpfval.n ( 𝜑𝑁 ∈ ℕ0 )
5 taylpfval.b ( 𝜑𝐵 ∈ dom ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑁 ) )
6 taylpfval.t 𝑇 = ( 𝑁 ( 𝑆 Tayl 𝐹 ) 𝐵 )
7 taylply2.1 ( 𝜑𝐷 ∈ ( SubRing ‘ ℂfld ) )
8 taylply2.2 ( 𝜑𝐵𝐷 )
9 taylply2.3 ( ( 𝜑𝑘 ∈ ( 0 ... 𝑁 ) ) → ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) ∈ 𝐷 )
10 1 2 3 4 5 6 taylpfval ( 𝜑𝑇 = ( 𝑥 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( ( 𝑥𝐵 ) ↑ 𝑘 ) ) ) )
11 simpr ( ( 𝜑𝑥 ∈ ℂ ) → 𝑥 ∈ ℂ )
12 cnex ℂ ∈ V
13 12 a1i ( 𝜑 → ℂ ∈ V )
14 elpm2r ( ( ( ℂ ∈ V ∧ 𝑆 ∈ { ℝ , ℂ } ) ∧ ( 𝐹 : 𝐴 ⟶ ℂ ∧ 𝐴𝑆 ) ) → 𝐹 ∈ ( ℂ ↑pm 𝑆 ) )
15 13 1 2 3 14 syl22anc ( 𝜑𝐹 ∈ ( ℂ ↑pm 𝑆 ) )
16 dvnbss ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ∧ 𝑁 ∈ ℕ0 ) → dom ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑁 ) ⊆ dom 𝐹 )
17 1 15 4 16 syl3anc ( 𝜑 → dom ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑁 ) ⊆ dom 𝐹 )
18 2 17 fssdmd ( 𝜑 → dom ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑁 ) ⊆ 𝐴 )
19 recnprss ( 𝑆 ∈ { ℝ , ℂ } → 𝑆 ⊆ ℂ )
20 1 19 syl ( 𝜑𝑆 ⊆ ℂ )
21 3 20 sstrd ( 𝜑𝐴 ⊆ ℂ )
22 18 21 sstrd ( 𝜑 → dom ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑁 ) ⊆ ℂ )
23 22 5 sseldd ( 𝜑𝐵 ∈ ℂ )
24 23 adantr ( ( 𝜑𝑥 ∈ ℂ ) → 𝐵 ∈ ℂ )
25 11 24 subcld ( ( 𝜑𝑥 ∈ ℂ ) → ( 𝑥𝐵 ) ∈ ℂ )
26 df-idp Xp = ( I ↾ ℂ )
27 mptresid ( I ↾ ℂ ) = ( 𝑥 ∈ ℂ ↦ 𝑥 )
28 26 27 eqtri Xp = ( 𝑥 ∈ ℂ ↦ 𝑥 )
29 28 a1i ( 𝜑Xp = ( 𝑥 ∈ ℂ ↦ 𝑥 ) )
30 fconstmpt ( ℂ × { 𝐵 } ) = ( 𝑥 ∈ ℂ ↦ 𝐵 )
31 30 a1i ( 𝜑 → ( ℂ × { 𝐵 } ) = ( 𝑥 ∈ ℂ ↦ 𝐵 ) )
32 13 11 24 29 31 offval2 ( 𝜑 → ( Xpf − ( ℂ × { 𝐵 } ) ) = ( 𝑥 ∈ ℂ ↦ ( 𝑥𝐵 ) ) )
33 eqidd ( 𝜑 → ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) = ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) )
34 oveq1 ( 𝑦 = ( 𝑥𝐵 ) → ( 𝑦𝑘 ) = ( ( 𝑥𝐵 ) ↑ 𝑘 ) )
35 34 oveq2d ( 𝑦 = ( 𝑥𝐵 ) → ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) = ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( ( 𝑥𝐵 ) ↑ 𝑘 ) ) )
36 35 sumeq2sdv ( 𝑦 = ( 𝑥𝐵 ) → Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) = Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( ( 𝑥𝐵 ) ↑ 𝑘 ) ) )
37 25 32 33 36 fmptco ( 𝜑 → ( ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ∘ ( Xpf − ( ℂ × { 𝐵 } ) ) ) = ( 𝑥 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( ( 𝑥𝐵 ) ↑ 𝑘 ) ) ) )
38 10 37 eqtr4d ( 𝜑𝑇 = ( ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ∘ ( Xpf − ( ℂ × { 𝐵 } ) ) ) )
39 cnfldbas ℂ = ( Base ‘ ℂfld )
40 39 subrgss ( 𝐷 ∈ ( SubRing ‘ ℂfld ) → 𝐷 ⊆ ℂ )
41 7 40 syl ( 𝜑𝐷 ⊆ ℂ )
42 41 4 9 elplyd ( 𝜑 → ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ∈ ( Poly ‘ 𝐷 ) )
43 cnfld1 1 = ( 1r ‘ ℂfld )
44 43 subrg1cl ( 𝐷 ∈ ( SubRing ‘ ℂfld ) → 1 ∈ 𝐷 )
45 7 44 syl ( 𝜑 → 1 ∈ 𝐷 )
46 plyid ( ( 𝐷 ⊆ ℂ ∧ 1 ∈ 𝐷 ) → Xp ∈ ( Poly ‘ 𝐷 ) )
47 41 45 46 syl2anc ( 𝜑Xp ∈ ( Poly ‘ 𝐷 ) )
48 plyconst ( ( 𝐷 ⊆ ℂ ∧ 𝐵𝐷 ) → ( ℂ × { 𝐵 } ) ∈ ( Poly ‘ 𝐷 ) )
49 41 8 48 syl2anc ( 𝜑 → ( ℂ × { 𝐵 } ) ∈ ( Poly ‘ 𝐷 ) )
50 subrgsubg ( 𝐷 ∈ ( SubRing ‘ ℂfld ) → 𝐷 ∈ ( SubGrp ‘ ℂfld ) )
51 7 50 syl ( 𝜑𝐷 ∈ ( SubGrp ‘ ℂfld ) )
52 cnfldadd + = ( +g ‘ ℂfld )
53 52 subgcl ( ( 𝐷 ∈ ( SubGrp ‘ ℂfld ) ∧ 𝑢𝐷𝑣𝐷 ) → ( 𝑢 + 𝑣 ) ∈ 𝐷 )
54 53 3expb ( ( 𝐷 ∈ ( SubGrp ‘ ℂfld ) ∧ ( 𝑢𝐷𝑣𝐷 ) ) → ( 𝑢 + 𝑣 ) ∈ 𝐷 )
55 51 54 sylan ( ( 𝜑 ∧ ( 𝑢𝐷𝑣𝐷 ) ) → ( 𝑢 + 𝑣 ) ∈ 𝐷 )
56 cnfldmul · = ( .r ‘ ℂfld )
57 56 subrgmcl ( ( 𝐷 ∈ ( SubRing ‘ ℂfld ) ∧ 𝑢𝐷𝑣𝐷 ) → ( 𝑢 · 𝑣 ) ∈ 𝐷 )
58 57 3expb ( ( 𝐷 ∈ ( SubRing ‘ ℂfld ) ∧ ( 𝑢𝐷𝑣𝐷 ) ) → ( 𝑢 · 𝑣 ) ∈ 𝐷 )
59 7 58 sylan ( ( 𝜑 ∧ ( 𝑢𝐷𝑣𝐷 ) ) → ( 𝑢 · 𝑣 ) ∈ 𝐷 )
60 ax-1cn 1 ∈ ℂ
61 cnfldneg ( 1 ∈ ℂ → ( ( invg ‘ ℂfld ) ‘ 1 ) = - 1 )
62 60 61 ax-mp ( ( invg ‘ ℂfld ) ‘ 1 ) = - 1
63 eqid ( invg ‘ ℂfld ) = ( invg ‘ ℂfld )
64 63 subginvcl ( ( 𝐷 ∈ ( SubGrp ‘ ℂfld ) ∧ 1 ∈ 𝐷 ) → ( ( invg ‘ ℂfld ) ‘ 1 ) ∈ 𝐷 )
65 51 45 64 syl2anc ( 𝜑 → ( ( invg ‘ ℂfld ) ‘ 1 ) ∈ 𝐷 )
66 62 65 eqeltrrid ( 𝜑 → - 1 ∈ 𝐷 )
67 47 49 55 59 66 plysub ( 𝜑 → ( Xpf − ( ℂ × { 𝐵 } ) ) ∈ ( Poly ‘ 𝐷 ) )
68 42 67 55 59 plyco ( 𝜑 → ( ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ∘ ( Xpf − ( ℂ × { 𝐵 } ) ) ) ∈ ( Poly ‘ 𝐷 ) )
69 38 68 eqeltrd ( 𝜑𝑇 ∈ ( Poly ‘ 𝐷 ) )
70 38 fveq2d ( 𝜑 → ( deg ‘ 𝑇 ) = ( deg ‘ ( ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ∘ ( Xpf − ( ℂ × { 𝐵 } ) ) ) ) )
71 eqid ( deg ‘ ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ) = ( deg ‘ ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) )
72 eqid ( deg ‘ ( Xpf − ( ℂ × { 𝐵 } ) ) ) = ( deg ‘ ( Xpf − ( ℂ × { 𝐵 } ) ) )
73 71 72 42 67 dgrco ( 𝜑 → ( deg ‘ ( ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ∘ ( Xpf − ( ℂ × { 𝐵 } ) ) ) ) = ( ( deg ‘ ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ) · ( deg ‘ ( Xpf − ( ℂ × { 𝐵 } ) ) ) ) )
74 eqid ( Xpf − ( ℂ × { 𝐵 } ) ) = ( Xpf − ( ℂ × { 𝐵 } ) )
75 74 plyremlem ( 𝐵 ∈ ℂ → ( ( Xpf − ( ℂ × { 𝐵 } ) ) ∈ ( Poly ‘ ℂ ) ∧ ( deg ‘ ( Xpf − ( ℂ × { 𝐵 } ) ) ) = 1 ∧ ( ( Xpf − ( ℂ × { 𝐵 } ) ) “ { 0 } ) = { 𝐵 } ) )
76 23 75 syl ( 𝜑 → ( ( Xpf − ( ℂ × { 𝐵 } ) ) ∈ ( Poly ‘ ℂ ) ∧ ( deg ‘ ( Xpf − ( ℂ × { 𝐵 } ) ) ) = 1 ∧ ( ( Xpf − ( ℂ × { 𝐵 } ) ) “ { 0 } ) = { 𝐵 } ) )
77 76 simp2d ( 𝜑 → ( deg ‘ ( Xpf − ( ℂ × { 𝐵 } ) ) ) = 1 )
78 77 oveq2d ( 𝜑 → ( ( deg ‘ ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ) · ( deg ‘ ( Xpf − ( ℂ × { 𝐵 } ) ) ) ) = ( ( deg ‘ ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ) · 1 ) )
79 dgrcl ( ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ∈ ( Poly ‘ 𝐷 ) → ( deg ‘ ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ) ∈ ℕ0 )
80 42 79 syl ( 𝜑 → ( deg ‘ ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ) ∈ ℕ0 )
81 80 nn0cnd ( 𝜑 → ( deg ‘ ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ) ∈ ℂ )
82 81 mulid1d ( 𝜑 → ( ( deg ‘ ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ) · 1 ) = ( deg ‘ ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ) )
83 78 82 eqtrd ( 𝜑 → ( ( deg ‘ ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ) · ( deg ‘ ( Xpf − ( ℂ × { 𝐵 } ) ) ) ) = ( deg ‘ ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ) )
84 70 73 83 3eqtrd ( 𝜑 → ( deg ‘ 𝑇 ) = ( deg ‘ ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ) )
85 1 adantr ( ( 𝜑𝑘 ∈ ( 0 ... 𝑁 ) ) → 𝑆 ∈ { ℝ , ℂ } )
86 15 adantr ( ( 𝜑𝑘 ∈ ( 0 ... 𝑁 ) ) → 𝐹 ∈ ( ℂ ↑pm 𝑆 ) )
87 elfznn0 ( 𝑘 ∈ ( 0 ... 𝑁 ) → 𝑘 ∈ ℕ0 )
88 87 adantl ( ( 𝜑𝑘 ∈ ( 0 ... 𝑁 ) ) → 𝑘 ∈ ℕ0 )
89 dvnf ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ∧ 𝑘 ∈ ℕ0 ) → ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) : dom ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ⟶ ℂ )
90 85 86 88 89 syl3anc ( ( 𝜑𝑘 ∈ ( 0 ... 𝑁 ) ) → ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) : dom ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ⟶ ℂ )
91 simpr ( ( 𝜑𝑘 ∈ ( 0 ... 𝑁 ) ) → 𝑘 ∈ ( 0 ... 𝑁 ) )
92 dvn2bss ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ∧ 𝑘 ∈ ( 0 ... 𝑁 ) ) → dom ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑁 ) ⊆ dom ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) )
93 85 86 91 92 syl3anc ( ( 𝜑𝑘 ∈ ( 0 ... 𝑁 ) ) → dom ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑁 ) ⊆ dom ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) )
94 5 adantr ( ( 𝜑𝑘 ∈ ( 0 ... 𝑁 ) ) → 𝐵 ∈ dom ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑁 ) )
95 93 94 sseldd ( ( 𝜑𝑘 ∈ ( 0 ... 𝑁 ) ) → 𝐵 ∈ dom ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) )
96 90 95 ffvelrnd ( ( 𝜑𝑘 ∈ ( 0 ... 𝑁 ) ) → ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) ∈ ℂ )
97 88 faccld ( ( 𝜑𝑘 ∈ ( 0 ... 𝑁 ) ) → ( ! ‘ 𝑘 ) ∈ ℕ )
98 97 nncnd ( ( 𝜑𝑘 ∈ ( 0 ... 𝑁 ) ) → ( ! ‘ 𝑘 ) ∈ ℂ )
99 97 nnne0d ( ( 𝜑𝑘 ∈ ( 0 ... 𝑁 ) ) → ( ! ‘ 𝑘 ) ≠ 0 )
100 96 98 99 divcld ( ( 𝜑𝑘 ∈ ( 0 ... 𝑁 ) ) → ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) ∈ ℂ )
101 42 4 100 33 dgrle ( 𝜑 → ( deg ‘ ( 𝑦 ∈ ℂ ↦ Σ 𝑘 ∈ ( 0 ... 𝑁 ) ( ( ( ( ( 𝑆 D𝑛 𝐹 ) ‘ 𝑘 ) ‘ 𝐵 ) / ( ! ‘ 𝑘 ) ) · ( 𝑦𝑘 ) ) ) ) ≤ 𝑁 )
102 84 101 eqbrtrd ( 𝜑 → ( deg ‘ 𝑇 ) ≤ 𝑁 )
103 69 102 jca ( 𝜑 → ( 𝑇 ∈ ( Poly ‘ 𝐷 ) ∧ ( deg ‘ 𝑇 ) ≤ 𝑁 ) )