Proof of Theorem ax5seglem1
| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | simpl2l 1227 | . . . . 5
⊢ (((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ (𝑇 ∈ (0[,]1) ∧ ∀𝑖 ∈ (1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖))))) ∧ 𝑗 ∈ (1...𝑁)) → 𝐴 ∈ (𝔼‘𝑁)) | 
| 2 |  | fveecn 28917 | . . . . 5
⊢ ((𝐴 ∈ (𝔼‘𝑁) ∧ 𝑗 ∈ (1...𝑁)) → (𝐴‘𝑗) ∈ ℂ) | 
| 3 | 1, 2 | sylancom 588 | . . . 4
⊢ (((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ (𝑇 ∈ (0[,]1) ∧ ∀𝑖 ∈ (1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖))))) ∧ 𝑗 ∈ (1...𝑁)) → (𝐴‘𝑗) ∈ ℂ) | 
| 4 |  | simpl2r 1228 | . . . . 5
⊢ (((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ (𝑇 ∈ (0[,]1) ∧ ∀𝑖 ∈ (1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖))))) ∧ 𝑗 ∈ (1...𝑁)) → 𝐶 ∈ (𝔼‘𝑁)) | 
| 5 |  | fveecn 28917 | . . . . 5
⊢ ((𝐶 ∈ (𝔼‘𝑁) ∧ 𝑗 ∈ (1...𝑁)) → (𝐶‘𝑗) ∈ ℂ) | 
| 6 | 4, 5 | sylancom 588 | . . . 4
⊢ (((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ (𝑇 ∈ (0[,]1) ∧ ∀𝑖 ∈ (1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖))))) ∧ 𝑗 ∈ (1...𝑁)) → (𝐶‘𝑗) ∈ ℂ) | 
| 7 |  | elicc01 13506 | . . . . . . . . 9
⊢ (𝑇 ∈ (0[,]1) ↔ (𝑇 ∈ ℝ ∧ 0 ≤
𝑇 ∧ 𝑇 ≤ 1)) | 
| 8 | 7 | simp1bi 1146 | . . . . . . . 8
⊢ (𝑇 ∈ (0[,]1) → 𝑇 ∈
ℝ) | 
| 9 | 8 | adantr 480 | . . . . . . 7
⊢ ((𝑇 ∈ (0[,]1) ∧
∀𝑖 ∈ (1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖)))) → 𝑇 ∈ ℝ) | 
| 10 | 9 | 3ad2ant3 1136 | . . . . . 6
⊢ ((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ (𝑇 ∈ (0[,]1) ∧ ∀𝑖 ∈ (1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖))))) → 𝑇 ∈ ℝ) | 
| 11 | 10 | recnd 11289 | . . . . 5
⊢ ((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ (𝑇 ∈ (0[,]1) ∧ ∀𝑖 ∈ (1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖))))) → 𝑇 ∈ ℂ) | 
| 12 | 11 | adantr 480 | . . . 4
⊢ (((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ (𝑇 ∈ (0[,]1) ∧ ∀𝑖 ∈ (1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖))))) ∧ 𝑗 ∈ (1...𝑁)) → 𝑇 ∈ ℂ) | 
| 13 |  | fveq2 6906 | . . . . . . . 8
⊢ (𝑖 = 𝑗 → (𝐵‘𝑖) = (𝐵‘𝑗)) | 
| 14 |  | fveq2 6906 | . . . . . . . . . 10
⊢ (𝑖 = 𝑗 → (𝐴‘𝑖) = (𝐴‘𝑗)) | 
| 15 | 14 | oveq2d 7447 | . . . . . . . . 9
⊢ (𝑖 = 𝑗 → ((1 − 𝑇) · (𝐴‘𝑖)) = ((1 − 𝑇) · (𝐴‘𝑗))) | 
| 16 |  | fveq2 6906 | . . . . . . . . . 10
⊢ (𝑖 = 𝑗 → (𝐶‘𝑖) = (𝐶‘𝑗)) | 
| 17 | 16 | oveq2d 7447 | . . . . . . . . 9
⊢ (𝑖 = 𝑗 → (𝑇 · (𝐶‘𝑖)) = (𝑇 · (𝐶‘𝑗))) | 
| 18 | 15, 17 | oveq12d 7449 | . . . . . . . 8
⊢ (𝑖 = 𝑗 → (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖))) = (((1 − 𝑇) · (𝐴‘𝑗)) + (𝑇 · (𝐶‘𝑗)))) | 
| 19 | 13, 18 | eqeq12d 2753 | . . . . . . 7
⊢ (𝑖 = 𝑗 → ((𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖))) ↔ (𝐵‘𝑗) = (((1 − 𝑇) · (𝐴‘𝑗)) + (𝑇 · (𝐶‘𝑗))))) | 
| 20 | 19 | rspccva 3621 | . . . . . 6
⊢
((∀𝑖 ∈
(1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖))) ∧ 𝑗 ∈ (1...𝑁)) → (𝐵‘𝑗) = (((1 − 𝑇) · (𝐴‘𝑗)) + (𝑇 · (𝐶‘𝑗)))) | 
| 21 | 20 | adantll 714 | . . . . 5
⊢ (((𝑇 ∈ (0[,]1) ∧
∀𝑖 ∈ (1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖)))) ∧ 𝑗 ∈ (1...𝑁)) → (𝐵‘𝑗) = (((1 − 𝑇) · (𝐴‘𝑗)) + (𝑇 · (𝐶‘𝑗)))) | 
| 22 | 21 | 3ad2antl3 1188 | . . . 4
⊢ (((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ (𝑇 ∈ (0[,]1) ∧ ∀𝑖 ∈ (1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖))))) ∧ 𝑗 ∈ (1...𝑁)) → (𝐵‘𝑗) = (((1 − 𝑇) · (𝐴‘𝑗)) + (𝑇 · (𝐶‘𝑗)))) | 
| 23 |  | oveq2 7439 | . . . . . 6
⊢ ((𝐵‘𝑗) = (((1 − 𝑇) · (𝐴‘𝑗)) + (𝑇 · (𝐶‘𝑗))) → ((𝐴‘𝑗) − (𝐵‘𝑗)) = ((𝐴‘𝑗) − (((1 − 𝑇) · (𝐴‘𝑗)) + (𝑇 · (𝐶‘𝑗))))) | 
| 24 | 23 | oveq1d 7446 | . . . . 5
⊢ ((𝐵‘𝑗) = (((1 − 𝑇) · (𝐴‘𝑗)) + (𝑇 · (𝐶‘𝑗))) → (((𝐴‘𝑗) − (𝐵‘𝑗))↑2) = (((𝐴‘𝑗) − (((1 − 𝑇) · (𝐴‘𝑗)) + (𝑇 · (𝐶‘𝑗))))↑2)) | 
| 25 |  | subdi 11696 | . . . . . . . . 9
⊢ ((𝑇 ∈ ℂ ∧ (𝐴‘𝑗) ∈ ℂ ∧ (𝐶‘𝑗) ∈ ℂ) → (𝑇 · ((𝐴‘𝑗) − (𝐶‘𝑗))) = ((𝑇 · (𝐴‘𝑗)) − (𝑇 · (𝐶‘𝑗)))) | 
| 26 | 25 | 3coml 1128 | . . . . . . . 8
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ (𝐶‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → (𝑇 · ((𝐴‘𝑗) − (𝐶‘𝑗))) = ((𝑇 · (𝐴‘𝑗)) − (𝑇 · (𝐶‘𝑗)))) | 
| 27 |  | ax-1cn 11213 | . . . . . . . . . . . 12
⊢ 1 ∈
ℂ | 
| 28 |  | subcl 11507 | . . . . . . . . . . . . . 14
⊢ ((1
∈ ℂ ∧ 𝑇
∈ ℂ) → (1 − 𝑇) ∈ ℂ) | 
| 29 | 27, 28 | mpan 690 | . . . . . . . . . . . . 13
⊢ (𝑇 ∈ ℂ → (1
− 𝑇) ∈
ℂ) | 
| 30 | 29 | adantl 481 | . . . . . . . . . . . 12
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → (1 − 𝑇) ∈
ℂ) | 
| 31 |  | simpl 482 | . . . . . . . . . . . 12
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → (𝐴‘𝑗) ∈ ℂ) | 
| 32 |  | subdir 11697 | . . . . . . . . . . . 12
⊢ ((1
∈ ℂ ∧ (1 − 𝑇) ∈ ℂ ∧ (𝐴‘𝑗) ∈ ℂ) → ((1 − (1
− 𝑇)) · (𝐴‘𝑗)) = ((1 · (𝐴‘𝑗)) − ((1 − 𝑇) · (𝐴‘𝑗)))) | 
| 33 | 27, 30, 31, 32 | mp3an2i 1468 | . . . . . . . . . . 11
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → ((1 − (1
− 𝑇)) · (𝐴‘𝑗)) = ((1 · (𝐴‘𝑗)) − ((1 − 𝑇) · (𝐴‘𝑗)))) | 
| 34 |  | nncan 11538 | . . . . . . . . . . . . . 14
⊢ ((1
∈ ℂ ∧ 𝑇
∈ ℂ) → (1 − (1 − 𝑇)) = 𝑇) | 
| 35 | 27, 34 | mpan 690 | . . . . . . . . . . . . 13
⊢ (𝑇 ∈ ℂ → (1
− (1 − 𝑇)) =
𝑇) | 
| 36 | 35 | oveq1d 7446 | . . . . . . . . . . . 12
⊢ (𝑇 ∈ ℂ → ((1
− (1 − 𝑇))
· (𝐴‘𝑗)) = (𝑇 · (𝐴‘𝑗))) | 
| 37 | 36 | adantl 481 | . . . . . . . . . . 11
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → ((1 − (1
− 𝑇)) · (𝐴‘𝑗)) = (𝑇 · (𝐴‘𝑗))) | 
| 38 |  | mullid 11260 | . . . . . . . . . . . . 13
⊢ ((𝐴‘𝑗) ∈ ℂ → (1 · (𝐴‘𝑗)) = (𝐴‘𝑗)) | 
| 39 | 38 | oveq1d 7446 | . . . . . . . . . . . 12
⊢ ((𝐴‘𝑗) ∈ ℂ → ((1 · (𝐴‘𝑗)) − ((1 − 𝑇) · (𝐴‘𝑗))) = ((𝐴‘𝑗) − ((1 − 𝑇) · (𝐴‘𝑗)))) | 
| 40 | 39 | adantr 480 | . . . . . . . . . . 11
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → ((1 · (𝐴‘𝑗)) − ((1 − 𝑇) · (𝐴‘𝑗))) = ((𝐴‘𝑗) − ((1 − 𝑇) · (𝐴‘𝑗)))) | 
| 41 | 33, 37, 40 | 3eqtr3rd 2786 | . . . . . . . . . 10
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → ((𝐴‘𝑗) − ((1 − 𝑇) · (𝐴‘𝑗))) = (𝑇 · (𝐴‘𝑗))) | 
| 42 | 41 | oveq1d 7446 | . . . . . . . . 9
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → (((𝐴‘𝑗) − ((1 − 𝑇) · (𝐴‘𝑗))) − (𝑇 · (𝐶‘𝑗))) = ((𝑇 · (𝐴‘𝑗)) − (𝑇 · (𝐶‘𝑗)))) | 
| 43 | 42 | 3adant2 1132 | . . . . . . . 8
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ (𝐶‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → (((𝐴‘𝑗) − ((1 − 𝑇) · (𝐴‘𝑗))) − (𝑇 · (𝐶‘𝑗))) = ((𝑇 · (𝐴‘𝑗)) − (𝑇 · (𝐶‘𝑗)))) | 
| 44 |  | simp1 1137 | . . . . . . . . 9
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ (𝐶‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → (𝐴‘𝑗) ∈ ℂ) | 
| 45 |  | mulcl 11239 | . . . . . . . . . . . 12
⊢ (((1
− 𝑇) ∈ ℂ
∧ (𝐴‘𝑗) ∈ ℂ) → ((1
− 𝑇) · (𝐴‘𝑗)) ∈ ℂ) | 
| 46 | 29, 45 | sylan 580 | . . . . . . . . . . 11
⊢ ((𝑇 ∈ ℂ ∧ (𝐴‘𝑗) ∈ ℂ) → ((1 − 𝑇) · (𝐴‘𝑗)) ∈ ℂ) | 
| 47 | 46 | ancoms 458 | . . . . . . . . . 10
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → ((1 − 𝑇) · (𝐴‘𝑗)) ∈ ℂ) | 
| 48 | 47 | 3adant2 1132 | . . . . . . . . 9
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ (𝐶‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → ((1 − 𝑇) · (𝐴‘𝑗)) ∈ ℂ) | 
| 49 |  | mulcl 11239 | . . . . . . . . . . 11
⊢ ((𝑇 ∈ ℂ ∧ (𝐶‘𝑗) ∈ ℂ) → (𝑇 · (𝐶‘𝑗)) ∈ ℂ) | 
| 50 | 49 | ancoms 458 | . . . . . . . . . 10
⊢ (((𝐶‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → (𝑇 · (𝐶‘𝑗)) ∈ ℂ) | 
| 51 | 50 | 3adant1 1131 | . . . . . . . . 9
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ (𝐶‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → (𝑇 · (𝐶‘𝑗)) ∈ ℂ) | 
| 52 | 44, 48, 51 | subsub4d 11651 | . . . . . . . 8
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ (𝐶‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → (((𝐴‘𝑗) − ((1 − 𝑇) · (𝐴‘𝑗))) − (𝑇 · (𝐶‘𝑗))) = ((𝐴‘𝑗) − (((1 − 𝑇) · (𝐴‘𝑗)) + (𝑇 · (𝐶‘𝑗))))) | 
| 53 | 26, 43, 52 | 3eqtr2rd 2784 | . . . . . . 7
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ (𝐶‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → ((𝐴‘𝑗) − (((1 − 𝑇) · (𝐴‘𝑗)) + (𝑇 · (𝐶‘𝑗)))) = (𝑇 · ((𝐴‘𝑗) − (𝐶‘𝑗)))) | 
| 54 | 53 | oveq1d 7446 | . . . . . 6
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ (𝐶‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → (((𝐴‘𝑗) − (((1 − 𝑇) · (𝐴‘𝑗)) + (𝑇 · (𝐶‘𝑗))))↑2) = ((𝑇 · ((𝐴‘𝑗) − (𝐶‘𝑗)))↑2)) | 
| 55 |  | simp3 1139 | . . . . . . 7
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ (𝐶‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → 𝑇 ∈ ℂ) | 
| 56 |  | subcl 11507 | . . . . . . . 8
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ (𝐶‘𝑗) ∈ ℂ) → ((𝐴‘𝑗) − (𝐶‘𝑗)) ∈ ℂ) | 
| 57 | 56 | 3adant3 1133 | . . . . . . 7
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ (𝐶‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → ((𝐴‘𝑗) − (𝐶‘𝑗)) ∈ ℂ) | 
| 58 | 55, 57 | sqmuld 14198 | . . . . . 6
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ (𝐶‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → ((𝑇 · ((𝐴‘𝑗) − (𝐶‘𝑗)))↑2) = ((𝑇↑2) · (((𝐴‘𝑗) − (𝐶‘𝑗))↑2))) | 
| 59 | 54, 58 | eqtrd 2777 | . . . . 5
⊢ (((𝐴‘𝑗) ∈ ℂ ∧ (𝐶‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) → (((𝐴‘𝑗) − (((1 − 𝑇) · (𝐴‘𝑗)) + (𝑇 · (𝐶‘𝑗))))↑2) = ((𝑇↑2) · (((𝐴‘𝑗) − (𝐶‘𝑗))↑2))) | 
| 60 | 24, 59 | sylan9eqr 2799 | . . . 4
⊢ ((((𝐴‘𝑗) ∈ ℂ ∧ (𝐶‘𝑗) ∈ ℂ ∧ 𝑇 ∈ ℂ) ∧ (𝐵‘𝑗) = (((1 − 𝑇) · (𝐴‘𝑗)) + (𝑇 · (𝐶‘𝑗)))) → (((𝐴‘𝑗) − (𝐵‘𝑗))↑2) = ((𝑇↑2) · (((𝐴‘𝑗) − (𝐶‘𝑗))↑2))) | 
| 61 | 3, 6, 12, 22, 60 | syl31anc 1375 | . . 3
⊢ (((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ (𝑇 ∈ (0[,]1) ∧ ∀𝑖 ∈ (1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖))))) ∧ 𝑗 ∈ (1...𝑁)) → (((𝐴‘𝑗) − (𝐵‘𝑗))↑2) = ((𝑇↑2) · (((𝐴‘𝑗) − (𝐶‘𝑗))↑2))) | 
| 62 | 61 | sumeq2dv 15738 | . 2
⊢ ((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ (𝑇 ∈ (0[,]1) ∧ ∀𝑖 ∈ (1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖))))) → Σ𝑗 ∈ (1...𝑁)(((𝐴‘𝑗) − (𝐵‘𝑗))↑2) = Σ𝑗 ∈ (1...𝑁)((𝑇↑2) · (((𝐴‘𝑗) − (𝐶‘𝑗))↑2))) | 
| 63 |  | fzfid 14014 | . . 3
⊢ ((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ (𝑇 ∈ (0[,]1) ∧ ∀𝑖 ∈ (1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖))))) → (1...𝑁) ∈ Fin) | 
| 64 | 8 | resqcld 14165 | . . . . . 6
⊢ (𝑇 ∈ (0[,]1) → (𝑇↑2) ∈
ℝ) | 
| 65 | 64 | recnd 11289 | . . . . 5
⊢ (𝑇 ∈ (0[,]1) → (𝑇↑2) ∈
ℂ) | 
| 66 | 65 | adantr 480 | . . . 4
⊢ ((𝑇 ∈ (0[,]1) ∧
∀𝑖 ∈ (1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖)))) → (𝑇↑2) ∈ ℂ) | 
| 67 | 66 | 3ad2ant3 1136 | . . 3
⊢ ((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ (𝑇 ∈ (0[,]1) ∧ ∀𝑖 ∈ (1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖))))) → (𝑇↑2) ∈ ℂ) | 
| 68 | 2 | 3adant1 1131 | . . . . . . . 8
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ (𝔼‘𝑁) ∧ 𝑗 ∈ (1...𝑁)) → (𝐴‘𝑗) ∈ ℂ) | 
| 69 | 68 | 3adant2r 1180 | . . . . . . 7
⊢ ((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ 𝑗 ∈ (1...𝑁)) → (𝐴‘𝑗) ∈ ℂ) | 
| 70 | 5 | 3adant1 1131 | . . . . . . . 8
⊢ ((𝑁 ∈ ℕ ∧ 𝐶 ∈ (𝔼‘𝑁) ∧ 𝑗 ∈ (1...𝑁)) → (𝐶‘𝑗) ∈ ℂ) | 
| 71 | 70 | 3adant2l 1179 | . . . . . . 7
⊢ ((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ 𝑗 ∈ (1...𝑁)) → (𝐶‘𝑗) ∈ ℂ) | 
| 72 | 69, 71 | subcld 11620 | . . . . . 6
⊢ ((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ 𝑗 ∈ (1...𝑁)) → ((𝐴‘𝑗) − (𝐶‘𝑗)) ∈ ℂ) | 
| 73 | 72 | sqcld 14184 | . . . . 5
⊢ ((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ 𝑗 ∈ (1...𝑁)) → (((𝐴‘𝑗) − (𝐶‘𝑗))↑2) ∈ ℂ) | 
| 74 | 73 | 3expa 1119 | . . . 4
⊢ (((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁))) ∧ 𝑗 ∈ (1...𝑁)) → (((𝐴‘𝑗) − (𝐶‘𝑗))↑2) ∈ ℂ) | 
| 75 | 74 | 3adantl3 1169 | . . 3
⊢ (((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ (𝑇 ∈ (0[,]1) ∧ ∀𝑖 ∈ (1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖))))) ∧ 𝑗 ∈ (1...𝑁)) → (((𝐴‘𝑗) − (𝐶‘𝑗))↑2) ∈ ℂ) | 
| 76 | 63, 67, 75 | fsummulc2 15820 | . 2
⊢ ((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ (𝑇 ∈ (0[,]1) ∧ ∀𝑖 ∈ (1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖))))) → ((𝑇↑2) · Σ𝑗 ∈ (1...𝑁)(((𝐴‘𝑗) − (𝐶‘𝑗))↑2)) = Σ𝑗 ∈ (1...𝑁)((𝑇↑2) · (((𝐴‘𝑗) − (𝐶‘𝑗))↑2))) | 
| 77 | 62, 76 | eqtr4d 2780 | 1
⊢ ((𝑁 ∈ ℕ ∧ (𝐴 ∈ (𝔼‘𝑁) ∧ 𝐶 ∈ (𝔼‘𝑁)) ∧ (𝑇 ∈ (0[,]1) ∧ ∀𝑖 ∈ (1...𝑁)(𝐵‘𝑖) = (((1 − 𝑇) · (𝐴‘𝑖)) + (𝑇 · (𝐶‘𝑖))))) → Σ𝑗 ∈ (1...𝑁)(((𝐴‘𝑗) − (𝐵‘𝑗))↑2) = ((𝑇↑2) · Σ𝑗 ∈ (1...𝑁)(((𝐴‘𝑗) − (𝐶‘𝑗))↑2))) |