Proof of Theorem dgrsub2
| Step | Hyp | Ref
| Expression |
| 1 | | simpr2 1196 |
. . 3
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → 𝑁 ∈ ℕ) |
| 2 | | dgr0 26302 |
. . . . 5
⊢
(deg‘0𝑝) = 0 |
| 3 | | nngt0 12297 |
. . . . 5
⊢ (𝑁 ∈ ℕ → 0 <
𝑁) |
| 4 | 2, 3 | eqbrtrid 5178 |
. . . 4
⊢ (𝑁 ∈ ℕ →
(deg‘0𝑝) < 𝑁) |
| 5 | | fveq2 6906 |
. . . . 5
⊢ ((𝐹 ∘f −
𝐺) = 0𝑝
→ (deg‘(𝐹
∘f − 𝐺)) =
(deg‘0𝑝)) |
| 6 | 5 | breq1d 5153 |
. . . 4
⊢ ((𝐹 ∘f −
𝐺) = 0𝑝
→ ((deg‘(𝐹
∘f − 𝐺)) < 𝑁 ↔ (deg‘0𝑝)
< 𝑁)) |
| 7 | 4, 6 | syl5ibrcom 247 |
. . 3
⊢ (𝑁 ∈ ℕ → ((𝐹 ∘f −
𝐺) = 0𝑝
→ (deg‘(𝐹
∘f − 𝐺)) < 𝑁)) |
| 8 | 1, 7 | syl 17 |
. 2
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → ((𝐹 ∘f − 𝐺) = 0𝑝 →
(deg‘(𝐹
∘f − 𝐺)) < 𝑁)) |
| 9 | | plyssc 26239 |
. . . . . . . 8
⊢
(Poly‘𝑆)
⊆ (Poly‘ℂ) |
| 10 | 9 | sseli 3979 |
. . . . . . 7
⊢ (𝐹 ∈ (Poly‘𝑆) → 𝐹 ∈
(Poly‘ℂ)) |
| 11 | | plyssc 26239 |
. . . . . . . 8
⊢
(Poly‘𝑇)
⊆ (Poly‘ℂ) |
| 12 | 11 | sseli 3979 |
. . . . . . 7
⊢ (𝐺 ∈ (Poly‘𝑇) → 𝐺 ∈
(Poly‘ℂ)) |
| 13 | | eqid 2737 |
. . . . . . . 8
⊢
(deg‘𝐹) =
(deg‘𝐹) |
| 14 | | eqid 2737 |
. . . . . . . 8
⊢
(deg‘𝐺) =
(deg‘𝐺) |
| 15 | 13, 14 | dgrsub 26312 |
. . . . . . 7
⊢ ((𝐹 ∈ (Poly‘ℂ)
∧ 𝐺 ∈
(Poly‘ℂ)) → (deg‘(𝐹 ∘f − 𝐺)) ≤ if((deg‘𝐹) ≤ (deg‘𝐺), (deg‘𝐺), (deg‘𝐹))) |
| 16 | 10, 12, 15 | syl2an 596 |
. . . . . 6
⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) → (deg‘(𝐹 ∘f − 𝐺)) ≤ if((deg‘𝐹) ≤ (deg‘𝐺), (deg‘𝐺), (deg‘𝐹))) |
| 17 | 16 | adantr 480 |
. . . . 5
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → (deg‘(𝐹 ∘f − 𝐺)) ≤ if((deg‘𝐹) ≤ (deg‘𝐺), (deg‘𝐺), (deg‘𝐹))) |
| 18 | | simpr1 1195 |
. . . . . . 7
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → (deg‘𝐺) = 𝑁) |
| 19 | | dgrsub2.a |
. . . . . . . . 9
⊢ 𝑁 = (deg‘𝐹) |
| 20 | 19 | eqcomi 2746 |
. . . . . . . 8
⊢
(deg‘𝐹) =
𝑁 |
| 21 | 20 | a1i 11 |
. . . . . . 7
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → (deg‘𝐹) = 𝑁) |
| 22 | 18, 21 | ifeq12d 4547 |
. . . . . 6
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → if((deg‘𝐹) ≤ (deg‘𝐺), (deg‘𝐺), (deg‘𝐹)) = if((deg‘𝐹) ≤ (deg‘𝐺), 𝑁, 𝑁)) |
| 23 | | ifid 4566 |
. . . . . 6
⊢
if((deg‘𝐹)
≤ (deg‘𝐺), 𝑁, 𝑁) = 𝑁 |
| 24 | 22, 23 | eqtrdi 2793 |
. . . . 5
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → if((deg‘𝐹) ≤ (deg‘𝐺), (deg‘𝐺), (deg‘𝐹)) = 𝑁) |
| 25 | 17, 24 | breqtrd 5169 |
. . . 4
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → (deg‘(𝐹 ∘f − 𝐺)) ≤ 𝑁) |
| 26 | | eqid 2737 |
. . . . . . . . 9
⊢
(coeff‘𝐹) =
(coeff‘𝐹) |
| 27 | | eqid 2737 |
. . . . . . . . 9
⊢
(coeff‘𝐺) =
(coeff‘𝐺) |
| 28 | 26, 27 | coesub 26296 |
. . . . . . . 8
⊢ ((𝐹 ∈ (Poly‘ℂ)
∧ 𝐺 ∈
(Poly‘ℂ)) → (coeff‘(𝐹 ∘f − 𝐺)) = ((coeff‘𝐹) ∘f −
(coeff‘𝐺))) |
| 29 | 10, 12, 28 | syl2an 596 |
. . . . . . 7
⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) → (coeff‘(𝐹 ∘f − 𝐺)) = ((coeff‘𝐹) ∘f −
(coeff‘𝐺))) |
| 30 | 29 | adantr 480 |
. . . . . 6
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → (coeff‘(𝐹 ∘f − 𝐺)) = ((coeff‘𝐹) ∘f −
(coeff‘𝐺))) |
| 31 | 30 | fveq1d 6908 |
. . . . 5
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → ((coeff‘(𝐹 ∘f − 𝐺))‘𝑁) = (((coeff‘𝐹) ∘f −
(coeff‘𝐺))‘𝑁)) |
| 32 | 1 | nnnn0d 12587 |
. . . . . 6
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → 𝑁 ∈
ℕ0) |
| 33 | 26 | coef3 26271 |
. . . . . . . . 9
⊢ (𝐹 ∈ (Poly‘𝑆) → (coeff‘𝐹):ℕ0⟶ℂ) |
| 34 | 33 | ad2antrr 726 |
. . . . . . . 8
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → (coeff‘𝐹):ℕ0⟶ℂ) |
| 35 | 34 | ffnd 6737 |
. . . . . . 7
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → (coeff‘𝐹) Fn ℕ0) |
| 36 | 27 | coef3 26271 |
. . . . . . . . 9
⊢ (𝐺 ∈ (Poly‘𝑇) → (coeff‘𝐺):ℕ0⟶ℂ) |
| 37 | 36 | ad2antlr 727 |
. . . . . . . 8
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → (coeff‘𝐺):ℕ0⟶ℂ) |
| 38 | 37 | ffnd 6737 |
. . . . . . 7
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → (coeff‘𝐺) Fn ℕ0) |
| 39 | | nn0ex 12532 |
. . . . . . . 8
⊢
ℕ0 ∈ V |
| 40 | 39 | a1i 11 |
. . . . . . 7
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → ℕ0 ∈
V) |
| 41 | | inidm 4227 |
. . . . . . 7
⊢
(ℕ0 ∩ ℕ0) =
ℕ0 |
| 42 | | simplr3 1218 |
. . . . . . 7
⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) ∧ 𝑁 ∈ ℕ0) →
((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁)) |
| 43 | | eqidd 2738 |
. . . . . . 7
⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) ∧ 𝑁 ∈ ℕ0) →
((coeff‘𝐺)‘𝑁) = ((coeff‘𝐺)‘𝑁)) |
| 44 | 35, 38, 40, 40, 41, 42, 43 | ofval 7708 |
. . . . . 6
⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) ∧ 𝑁 ∈ ℕ0) →
(((coeff‘𝐹)
∘f − (coeff‘𝐺))‘𝑁) = (((coeff‘𝐺)‘𝑁) − ((coeff‘𝐺)‘𝑁))) |
| 45 | 32, 44 | mpdan 687 |
. . . . 5
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → (((coeff‘𝐹) ∘f −
(coeff‘𝐺))‘𝑁) = (((coeff‘𝐺)‘𝑁) − ((coeff‘𝐺)‘𝑁))) |
| 46 | 37, 32 | ffvelcdmd 7105 |
. . . . . 6
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → ((coeff‘𝐺)‘𝑁) ∈ ℂ) |
| 47 | 46 | subidd 11608 |
. . . . 5
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → (((coeff‘𝐺)‘𝑁) − ((coeff‘𝐺)‘𝑁)) = 0) |
| 48 | 31, 45, 47 | 3eqtrd 2781 |
. . . 4
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → ((coeff‘(𝐹 ∘f − 𝐺))‘𝑁) = 0) |
| 49 | | plysubcl 26261 |
. . . . . . 7
⊢ ((𝐹 ∈ (Poly‘ℂ)
∧ 𝐺 ∈
(Poly‘ℂ)) → (𝐹 ∘f − 𝐺) ∈
(Poly‘ℂ)) |
| 50 | 10, 12, 49 | syl2an 596 |
. . . . . 6
⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) → (𝐹 ∘f − 𝐺) ∈
(Poly‘ℂ)) |
| 51 | 50 | adantr 480 |
. . . . 5
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → (𝐹 ∘f − 𝐺) ∈
(Poly‘ℂ)) |
| 52 | | eqid 2737 |
. . . . . 6
⊢
(deg‘(𝐹
∘f − 𝐺)) = (deg‘(𝐹 ∘f − 𝐺)) |
| 53 | | eqid 2737 |
. . . . . 6
⊢
(coeff‘(𝐹
∘f − 𝐺)) = (coeff‘(𝐹 ∘f − 𝐺)) |
| 54 | 52, 53 | dgrlt 26306 |
. . . . 5
⊢ (((𝐹 ∘f −
𝐺) ∈
(Poly‘ℂ) ∧ 𝑁 ∈ ℕ0) → (((𝐹 ∘f −
𝐺) = 0𝑝
∨ (deg‘(𝐹
∘f − 𝐺)) < 𝑁) ↔ ((deg‘(𝐹 ∘f − 𝐺)) ≤ 𝑁 ∧ ((coeff‘(𝐹 ∘f − 𝐺))‘𝑁) = 0))) |
| 55 | 51, 32, 54 | syl2anc 584 |
. . . 4
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → (((𝐹 ∘f − 𝐺) = 0𝑝 ∨
(deg‘(𝐹
∘f − 𝐺)) < 𝑁) ↔ ((deg‘(𝐹 ∘f − 𝐺)) ≤ 𝑁 ∧ ((coeff‘(𝐹 ∘f − 𝐺))‘𝑁) = 0))) |
| 56 | 25, 48, 55 | mpbir2and 713 |
. . 3
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → ((𝐹 ∘f − 𝐺) = 0𝑝 ∨
(deg‘(𝐹
∘f − 𝐺)) < 𝑁)) |
| 57 | 56 | ord 865 |
. 2
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → (¬ (𝐹 ∘f − 𝐺) = 0𝑝 →
(deg‘(𝐹
∘f − 𝐺)) < 𝑁)) |
| 58 | 8, 57 | pm2.61d 179 |
1
⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑇)) ∧ ((deg‘𝐺) = 𝑁 ∧ 𝑁 ∈ ℕ ∧ ((coeff‘𝐹)‘𝑁) = ((coeff‘𝐺)‘𝑁))) → (deg‘(𝐹 ∘f − 𝐺)) < 𝑁) |