Proof of Theorem coeid3
| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | dgrub.1 | . . . 4
⊢ 𝐴 = (coeff‘𝐹) | 
| 2 |  | dgrub.2 | . . . 4
⊢ 𝑁 = (deg‘𝐹) | 
| 3 | 1, 2 | coeid2 26279 | . . 3
⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝑋 ∈ ℂ) → (𝐹‘𝑋) = Σ𝑘 ∈ (0...𝑁)((𝐴‘𝑘) · (𝑋↑𝑘))) | 
| 4 | 3 | 3adant2 1131 | . 2
⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) → (𝐹‘𝑋) = Σ𝑘 ∈ (0...𝑁)((𝐴‘𝑘) · (𝑋↑𝑘))) | 
| 5 |  | fzss2 13605 | . . . 4
⊢ (𝑀 ∈
(ℤ≥‘𝑁) → (0...𝑁) ⊆ (0...𝑀)) | 
| 6 | 5 | 3ad2ant2 1134 | . . 3
⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) → (0...𝑁) ⊆ (0...𝑀)) | 
| 7 |  | elfznn0 13661 | . . . 4
⊢ (𝑘 ∈ (0...𝑁) → 𝑘 ∈ ℕ0) | 
| 8 | 1 | coef3 26272 | . . . . . . 7
⊢ (𝐹 ∈ (Poly‘𝑆) → 𝐴:ℕ0⟶ℂ) | 
| 9 | 8 | 3ad2ant1 1133 | . . . . . 6
⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) → 𝐴:ℕ0⟶ℂ) | 
| 10 | 9 | ffvelcdmda 7103 | . . . . 5
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ ℕ0) → (𝐴‘𝑘) ∈ ℂ) | 
| 11 |  | expcl 14121 | . . . . . 6
⊢ ((𝑋 ∈ ℂ ∧ 𝑘 ∈ ℕ0)
→ (𝑋↑𝑘) ∈
ℂ) | 
| 12 | 11 | 3ad2antl3 1187 | . . . . 5
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ ℕ0) → (𝑋↑𝑘) ∈ ℂ) | 
| 13 | 10, 12 | mulcld 11282 | . . . 4
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ ℕ0) → ((𝐴‘𝑘) · (𝑋↑𝑘)) ∈ ℂ) | 
| 14 | 7, 13 | sylan2 593 | . . 3
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ (0...𝑁)) → ((𝐴‘𝑘) · (𝑋↑𝑘)) ∈ ℂ) | 
| 15 |  | eldifn 4131 | . . . . . . 7
⊢ (𝑘 ∈ ((0...𝑀) ∖ (0...𝑁)) → ¬ 𝑘 ∈ (0...𝑁)) | 
| 16 | 15 | adantl 481 | . . . . . 6
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ ((0...𝑀) ∖ (0...𝑁))) → ¬ 𝑘 ∈ (0...𝑁)) | 
| 17 |  | simpl1 1191 | . . . . . . . . 9
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ ((0...𝑀) ∖ (0...𝑁))) → 𝐹 ∈ (Poly‘𝑆)) | 
| 18 |  | eldifi 4130 | . . . . . . . . . . . 12
⊢ (𝑘 ∈ ((0...𝑀) ∖ (0...𝑁)) → 𝑘 ∈ (0...𝑀)) | 
| 19 |  | elfzuz 13561 | . . . . . . . . . . . 12
⊢ (𝑘 ∈ (0...𝑀) → 𝑘 ∈
(ℤ≥‘0)) | 
| 20 | 18, 19 | syl 17 | . . . . . . . . . . 11
⊢ (𝑘 ∈ ((0...𝑀) ∖ (0...𝑁)) → 𝑘 ∈
(ℤ≥‘0)) | 
| 21 | 20 | adantl 481 | . . . . . . . . . 10
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ ((0...𝑀) ∖ (0...𝑁))) → 𝑘 ∈
(ℤ≥‘0)) | 
| 22 |  | nn0uz 12921 | . . . . . . . . . 10
⊢
ℕ0 = (ℤ≥‘0) | 
| 23 | 21, 22 | eleqtrrdi 2851 | . . . . . . . . 9
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ ((0...𝑀) ∖ (0...𝑁))) → 𝑘 ∈ ℕ0) | 
| 24 | 1, 2 | dgrub 26274 | . . . . . . . . . 10
⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝑘 ∈ ℕ0 ∧ (𝐴‘𝑘) ≠ 0) → 𝑘 ≤ 𝑁) | 
| 25 | 24 | 3expia 1121 | . . . . . . . . 9
⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝑘 ∈ ℕ0) → ((𝐴‘𝑘) ≠ 0 → 𝑘 ≤ 𝑁)) | 
| 26 | 17, 23, 25 | syl2anc 584 | . . . . . . . 8
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ ((0...𝑀) ∖ (0...𝑁))) → ((𝐴‘𝑘) ≠ 0 → 𝑘 ≤ 𝑁)) | 
| 27 |  | simpl2 1192 | . . . . . . . . . 10
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ ((0...𝑀) ∖ (0...𝑁))) → 𝑀 ∈ (ℤ≥‘𝑁)) | 
| 28 |  | eluzel2 12884 | . . . . . . . . . 10
⊢ (𝑀 ∈
(ℤ≥‘𝑁) → 𝑁 ∈ ℤ) | 
| 29 | 27, 28 | syl 17 | . . . . . . . . 9
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ ((0...𝑀) ∖ (0...𝑁))) → 𝑁 ∈ ℤ) | 
| 30 |  | elfz5 13557 | . . . . . . . . 9
⊢ ((𝑘 ∈
(ℤ≥‘0) ∧ 𝑁 ∈ ℤ) → (𝑘 ∈ (0...𝑁) ↔ 𝑘 ≤ 𝑁)) | 
| 31 | 21, 29, 30 | syl2anc 584 | . . . . . . . 8
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ ((0...𝑀) ∖ (0...𝑁))) → (𝑘 ∈ (0...𝑁) ↔ 𝑘 ≤ 𝑁)) | 
| 32 | 26, 31 | sylibrd 259 | . . . . . . 7
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ ((0...𝑀) ∖ (0...𝑁))) → ((𝐴‘𝑘) ≠ 0 → 𝑘 ∈ (0...𝑁))) | 
| 33 | 32 | necon1bd 2957 | . . . . . 6
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ ((0...𝑀) ∖ (0...𝑁))) → (¬ 𝑘 ∈ (0...𝑁) → (𝐴‘𝑘) = 0)) | 
| 34 | 16, 33 | mpd 15 | . . . . 5
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ ((0...𝑀) ∖ (0...𝑁))) → (𝐴‘𝑘) = 0) | 
| 35 | 34 | oveq1d 7447 | . . . 4
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ ((0...𝑀) ∖ (0...𝑁))) → ((𝐴‘𝑘) · (𝑋↑𝑘)) = (0 · (𝑋↑𝑘))) | 
| 36 |  | elfznn0 13661 | . . . . . . 7
⊢ (𝑘 ∈ (0...𝑀) → 𝑘 ∈ ℕ0) | 
| 37 | 18, 36 | syl 17 | . . . . . 6
⊢ (𝑘 ∈ ((0...𝑀) ∖ (0...𝑁)) → 𝑘 ∈ ℕ0) | 
| 38 | 37, 12 | sylan2 593 | . . . . 5
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ ((0...𝑀) ∖ (0...𝑁))) → (𝑋↑𝑘) ∈ ℂ) | 
| 39 | 38 | mul02d 11460 | . . . 4
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ ((0...𝑀) ∖ (0...𝑁))) → (0 · (𝑋↑𝑘)) = 0) | 
| 40 | 35, 39 | eqtrd 2776 | . . 3
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) ∧ 𝑘 ∈ ((0...𝑀) ∖ (0...𝑁))) → ((𝐴‘𝑘) · (𝑋↑𝑘)) = 0) | 
| 41 |  | fzfid 14015 | . . 3
⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) → (0...𝑀) ∈ Fin) | 
| 42 | 6, 14, 40, 41 | fsumss 15762 | . 2
⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) → Σ𝑘 ∈ (0...𝑁)((𝐴‘𝑘) · (𝑋↑𝑘)) = Σ𝑘 ∈ (0...𝑀)((𝐴‘𝑘) · (𝑋↑𝑘))) | 
| 43 | 4, 42 | eqtrd 2776 | 1
⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝑀 ∈ (ℤ≥‘𝑁) ∧ 𝑋 ∈ ℂ) → (𝐹‘𝑋) = Σ𝑘 ∈ (0...𝑀)((𝐴‘𝑘) · (𝑋↑𝑘))) |