Proof of Theorem chordthmlem4
| Step | Hyp | Ref
| Expression |
| 1 | | 1re 10039 |
. . . . . . . . 9
⊢ 1 ∈
ℝ |
| 2 | 1 | a1i 11 |
. . . . . . . 8
⊢ (𝜑 → 1 ∈
ℝ) |
| 3 | | unitssre 12319 |
. . . . . . . . 9
⊢ (0[,]1)
⊆ ℝ |
| 4 | | chordthmlem4.X |
. . . . . . . . 9
⊢ (𝜑 → 𝑋 ∈ (0[,]1)) |
| 5 | 3, 4 | sseldi 3601 |
. . . . . . . 8
⊢ (𝜑 → 𝑋 ∈ ℝ) |
| 6 | 2, 5 | resubcld 10458 |
. . . . . . 7
⊢ (𝜑 → (1 − 𝑋) ∈
ℝ) |
| 7 | 6 | recnd 10068 |
. . . . . 6
⊢ (𝜑 → (1 − 𝑋) ∈
ℂ) |
| 8 | 7 | abscld 14175 |
. . . . 5
⊢ (𝜑 → (abs‘(1 −
𝑋)) ∈
ℝ) |
| 9 | 8 | recnd 10068 |
. . . 4
⊢ (𝜑 → (abs‘(1 −
𝑋)) ∈
ℂ) |
| 10 | | chordthmlem4.B |
. . . . . . 7
⊢ (𝜑 → 𝐵 ∈ ℂ) |
| 11 | | chordthmlem4.A |
. . . . . . 7
⊢ (𝜑 → 𝐴 ∈ ℂ) |
| 12 | 10, 11 | subcld 10392 |
. . . . . 6
⊢ (𝜑 → (𝐵 − 𝐴) ∈ ℂ) |
| 13 | 12 | abscld 14175 |
. . . . 5
⊢ (𝜑 → (abs‘(𝐵 − 𝐴)) ∈ ℝ) |
| 14 | 13 | recnd 10068 |
. . . 4
⊢ (𝜑 → (abs‘(𝐵 − 𝐴)) ∈ ℂ) |
| 15 | 5 | recnd 10068 |
. . . . . 6
⊢ (𝜑 → 𝑋 ∈ ℂ) |
| 16 | 15 | abscld 14175 |
. . . . 5
⊢ (𝜑 → (abs‘𝑋) ∈
ℝ) |
| 17 | 16 | recnd 10068 |
. . . 4
⊢ (𝜑 → (abs‘𝑋) ∈
ℂ) |
| 18 | 9, 14, 17, 14 | mul4d 10248 |
. . 3
⊢ (𝜑 → (((abs‘(1 −
𝑋)) ·
(abs‘(𝐵 − 𝐴))) · ((abs‘𝑋) · (abs‘(𝐵 − 𝐴)))) = (((abs‘(1 − 𝑋)) · (abs‘𝑋)) · ((abs‘(𝐵 − 𝐴)) · (abs‘(𝐵 − 𝐴))))) |
| 19 | | chordthmlem4.P |
. . . . . . 7
⊢ (𝜑 → 𝑃 = ((𝑋 · 𝐴) + ((1 − 𝑋) · 𝐵))) |
| 20 | 15, 11 | mulcld 10060 |
. . . . . . . . . 10
⊢ (𝜑 → (𝑋 · 𝐴) ∈ ℂ) |
| 21 | 7, 10 | mulcld 10060 |
. . . . . . . . . 10
⊢ (𝜑 → ((1 − 𝑋) · 𝐵) ∈ ℂ) |
| 22 | 20, 21 | addcld 10059 |
. . . . . . . . 9
⊢ (𝜑 → ((𝑋 · 𝐴) + ((1 − 𝑋) · 𝐵)) ∈ ℂ) |
| 23 | 19, 22 | eqeltrd 2701 |
. . . . . . . 8
⊢ (𝜑 → 𝑃 ∈ ℂ) |
| 24 | 11, 23, 10, 15 | affineequiv2 24554 |
. . . . . . 7
⊢ (𝜑 → (𝑃 = ((𝑋 · 𝐴) + ((1 − 𝑋) · 𝐵)) ↔ (𝑃 − 𝐴) = ((1 − 𝑋) · (𝐵 − 𝐴)))) |
| 25 | 19, 24 | mpbid 222 |
. . . . . 6
⊢ (𝜑 → (𝑃 − 𝐴) = ((1 − 𝑋) · (𝐵 − 𝐴))) |
| 26 | 25 | fveq2d 6195 |
. . . . 5
⊢ (𝜑 → (abs‘(𝑃 − 𝐴)) = (abs‘((1 − 𝑋) · (𝐵 − 𝐴)))) |
| 27 | 7, 12 | absmuld 14193 |
. . . . 5
⊢ (𝜑 → (abs‘((1 −
𝑋) · (𝐵 − 𝐴))) = ((abs‘(1 − 𝑋)) · (abs‘(𝐵 − 𝐴)))) |
| 28 | 26, 27 | eqtrd 2656 |
. . . 4
⊢ (𝜑 → (abs‘(𝑃 − 𝐴)) = ((abs‘(1 − 𝑋)) · (abs‘(𝐵 − 𝐴)))) |
| 29 | 23, 10 | abssubd 14192 |
. . . . 5
⊢ (𝜑 → (abs‘(𝑃 − 𝐵)) = (abs‘(𝐵 − 𝑃))) |
| 30 | 11, 23, 10, 15 | affineequiv 24553 |
. . . . . . 7
⊢ (𝜑 → (𝑃 = ((𝑋 · 𝐴) + ((1 − 𝑋) · 𝐵)) ↔ (𝐵 − 𝑃) = (𝑋 · (𝐵 − 𝐴)))) |
| 31 | 19, 30 | mpbid 222 |
. . . . . 6
⊢ (𝜑 → (𝐵 − 𝑃) = (𝑋 · (𝐵 − 𝐴))) |
| 32 | 31 | fveq2d 6195 |
. . . . 5
⊢ (𝜑 → (abs‘(𝐵 − 𝑃)) = (abs‘(𝑋 · (𝐵 − 𝐴)))) |
| 33 | 15, 12 | absmuld 14193 |
. . . . 5
⊢ (𝜑 → (abs‘(𝑋 · (𝐵 − 𝐴))) = ((abs‘𝑋) · (abs‘(𝐵 − 𝐴)))) |
| 34 | 29, 32, 33 | 3eqtrd 2660 |
. . . 4
⊢ (𝜑 → (abs‘(𝑃 − 𝐵)) = ((abs‘𝑋) · (abs‘(𝐵 − 𝐴)))) |
| 35 | 28, 34 | oveq12d 6668 |
. . 3
⊢ (𝜑 → ((abs‘(𝑃 − 𝐴)) · (abs‘(𝑃 − 𝐵))) = (((abs‘(1 − 𝑋)) · (abs‘(𝐵 − 𝐴))) · ((abs‘𝑋) · (abs‘(𝐵 − 𝐴))))) |
| 36 | 14 | sqvald 13005 |
. . . 4
⊢ (𝜑 → ((abs‘(𝐵 − 𝐴))↑2) = ((abs‘(𝐵 − 𝐴)) · (abs‘(𝐵 − 𝐴)))) |
| 37 | 36 | oveq2d 6666 |
. . 3
⊢ (𝜑 → (((abs‘(1 −
𝑋)) ·
(abs‘𝑋)) ·
((abs‘(𝐵 −
𝐴))↑2)) =
(((abs‘(1 − 𝑋))
· (abs‘𝑋))
· ((abs‘(𝐵
− 𝐴)) ·
(abs‘(𝐵 − 𝐴))))) |
| 38 | 18, 35, 37 | 3eqtr4d 2666 |
. 2
⊢ (𝜑 → ((abs‘(𝑃 − 𝐴)) · (abs‘(𝑃 − 𝐵))) = (((abs‘(1 − 𝑋)) · (abs‘𝑋)) · ((abs‘(𝐵 − 𝐴))↑2))) |
| 39 | 2 | recnd 10068 |
. . . . . 6
⊢ (𝜑 → 1 ∈
ℂ) |
| 40 | 39 | halfcld 11277 |
. . . . 5
⊢ (𝜑 → (1 / 2) ∈
ℂ) |
| 41 | 40 | sqcld 13006 |
. . . 4
⊢ (𝜑 → ((1 / 2)↑2) ∈
ℂ) |
| 42 | 2 | rehalfcld 11279 |
. . . . . . . . 9
⊢ (𝜑 → (1 / 2) ∈
ℝ) |
| 43 | 42, 5 | resubcld 10458 |
. . . . . . . 8
⊢ (𝜑 → ((1 / 2) − 𝑋) ∈
ℝ) |
| 44 | 43 | recnd 10068 |
. . . . . . 7
⊢ (𝜑 → ((1 / 2) − 𝑋) ∈
ℂ) |
| 45 | 44 | abscld 14175 |
. . . . . 6
⊢ (𝜑 → (abs‘((1 / 2)
− 𝑋)) ∈
ℝ) |
| 46 | 45 | recnd 10068 |
. . . . 5
⊢ (𝜑 → (abs‘((1 / 2)
− 𝑋)) ∈
ℂ) |
| 47 | 46 | sqcld 13006 |
. . . 4
⊢ (𝜑 → ((abs‘((1 / 2)
− 𝑋))↑2) ∈
ℂ) |
| 48 | 14 | sqcld 13006 |
. . . 4
⊢ (𝜑 → ((abs‘(𝐵 − 𝐴))↑2) ∈ ℂ) |
| 49 | 41, 47, 48 | subdird 10487 |
. . 3
⊢ (𝜑 → ((((1 / 2)↑2) −
((abs‘((1 / 2) − 𝑋))↑2)) · ((abs‘(𝐵 − 𝐴))↑2)) = ((((1 / 2)↑2) ·
((abs‘(𝐵 −
𝐴))↑2)) −
(((abs‘((1 / 2) − 𝑋))↑2) · ((abs‘(𝐵 − 𝐴))↑2)))) |
| 50 | | subsq 12972 |
. . . . . . 7
⊢ (((1 / 2)
∈ ℂ ∧ ((1 / 2) − 𝑋) ∈ ℂ) → (((1 / 2)↑2)
− (((1 / 2) − 𝑋)↑2)) = (((1 / 2) + ((1 / 2) −
𝑋)) · ((1 / 2)
− ((1 / 2) − 𝑋)))) |
| 51 | 40, 44, 50 | syl2anc 693 |
. . . . . 6
⊢ (𝜑 → (((1 / 2)↑2) −
(((1 / 2) − 𝑋)↑2)) = (((1 / 2) + ((1 / 2) −
𝑋)) · ((1 / 2)
− ((1 / 2) − 𝑋)))) |
| 52 | 40, 40, 15 | addsubassd 10412 |
. . . . . . . 8
⊢ (𝜑 → (((1 / 2) + (1 / 2))
− 𝑋) = ((1 / 2) + ((1
/ 2) − 𝑋))) |
| 53 | 39 | 2halvesd 11278 |
. . . . . . . . 9
⊢ (𝜑 → ((1 / 2) + (1 / 2)) =
1) |
| 54 | 53 | oveq1d 6665 |
. . . . . . . 8
⊢ (𝜑 → (((1 / 2) + (1 / 2))
− 𝑋) = (1 −
𝑋)) |
| 55 | 52, 54 | eqtr3d 2658 |
. . . . . . 7
⊢ (𝜑 → ((1 / 2) + ((1 / 2)
− 𝑋)) = (1 −
𝑋)) |
| 56 | 40, 15 | nncand 10397 |
. . . . . . 7
⊢ (𝜑 → ((1 / 2) − ((1 / 2)
− 𝑋)) = 𝑋) |
| 57 | 55, 56 | oveq12d 6668 |
. . . . . 6
⊢ (𝜑 → (((1 / 2) + ((1 / 2)
− 𝑋)) · ((1 /
2) − ((1 / 2) − 𝑋))) = ((1 − 𝑋) · 𝑋)) |
| 58 | 51, 57 | eqtr2d 2657 |
. . . . 5
⊢ (𝜑 → ((1 − 𝑋) · 𝑋) = (((1 / 2)↑2) − (((1 / 2)
− 𝑋)↑2))) |
| 59 | | 0re 10040 |
. . . . . . . . . 10
⊢ 0 ∈
ℝ |
| 60 | 59, 1 | elicc2i 12239 |
. . . . . . . . 9
⊢ (𝑋 ∈ (0[,]1) ↔ (𝑋 ∈ ℝ ∧ 0 ≤
𝑋 ∧ 𝑋 ≤ 1)) |
| 61 | 4, 60 | sylib 208 |
. . . . . . . 8
⊢ (𝜑 → (𝑋 ∈ ℝ ∧ 0 ≤ 𝑋 ∧ 𝑋 ≤ 1)) |
| 62 | 61 | simp3d 1075 |
. . . . . . 7
⊢ (𝜑 → 𝑋 ≤ 1) |
| 63 | 5, 2, 62 | abssubge0d 14170 |
. . . . . 6
⊢ (𝜑 → (abs‘(1 −
𝑋)) = (1 − 𝑋)) |
| 64 | 61 | simp2d 1074 |
. . . . . . 7
⊢ (𝜑 → 0 ≤ 𝑋) |
| 65 | 5, 64 | absidd 14161 |
. . . . . 6
⊢ (𝜑 → (abs‘𝑋) = 𝑋) |
| 66 | 63, 65 | oveq12d 6668 |
. . . . 5
⊢ (𝜑 → ((abs‘(1 −
𝑋)) ·
(abs‘𝑋)) = ((1
− 𝑋) · 𝑋)) |
| 67 | | absresq 14042 |
. . . . . . 7
⊢ (((1 / 2)
− 𝑋) ∈ ℝ
→ ((abs‘((1 / 2) − 𝑋))↑2) = (((1 / 2) − 𝑋)↑2)) |
| 68 | 43, 67 | syl 17 |
. . . . . 6
⊢ (𝜑 → ((abs‘((1 / 2)
− 𝑋))↑2) = (((1
/ 2) − 𝑋)↑2)) |
| 69 | 68 | oveq2d 6666 |
. . . . 5
⊢ (𝜑 → (((1 / 2)↑2) −
((abs‘((1 / 2) − 𝑋))↑2)) = (((1 / 2)↑2) − (((1
/ 2) − 𝑋)↑2))) |
| 70 | 58, 66, 69 | 3eqtr4d 2666 |
. . . 4
⊢ (𝜑 → ((abs‘(1 −
𝑋)) ·
(abs‘𝑋)) = (((1 /
2)↑2) − ((abs‘((1 / 2) − 𝑋))↑2))) |
| 71 | 70 | oveq1d 6665 |
. . 3
⊢ (𝜑 → (((abs‘(1 −
𝑋)) ·
(abs‘𝑋)) ·
((abs‘(𝐵 −
𝐴))↑2)) = ((((1 /
2)↑2) − ((abs‘((1 / 2) − 𝑋))↑2)) · ((abs‘(𝐵 − 𝐴))↑2))) |
| 72 | | 2cnd 11093 |
. . . . . . . . . . . . 13
⊢ (𝜑 → 2 ∈
ℂ) |
| 73 | | 2ne0 11113 |
. . . . . . . . . . . . . 14
⊢ 2 ≠
0 |
| 74 | 73 | a1i 11 |
. . . . . . . . . . . . 13
⊢ (𝜑 → 2 ≠ 0) |
| 75 | 10, 72, 74 | divcan4d 10807 |
. . . . . . . . . . . 12
⊢ (𝜑 → ((𝐵 · 2) / 2) = 𝐵) |
| 76 | 10 | times2d 11276 |
. . . . . . . . . . . . 13
⊢ (𝜑 → (𝐵 · 2) = (𝐵 + 𝐵)) |
| 77 | 76 | oveq1d 6665 |
. . . . . . . . . . . 12
⊢ (𝜑 → ((𝐵 · 2) / 2) = ((𝐵 + 𝐵) / 2)) |
| 78 | 75, 77 | eqtr3d 2658 |
. . . . . . . . . . 11
⊢ (𝜑 → 𝐵 = ((𝐵 + 𝐵) / 2)) |
| 79 | | chordthmlem4.M |
. . . . . . . . . . 11
⊢ (𝜑 → 𝑀 = ((𝐴 + 𝐵) / 2)) |
| 80 | 78, 79 | oveq12d 6668 |
. . . . . . . . . 10
⊢ (𝜑 → (𝐵 − 𝑀) = (((𝐵 + 𝐵) / 2) − ((𝐴 + 𝐵) / 2))) |
| 81 | 10, 10 | addcld 10059 |
. . . . . . . . . . 11
⊢ (𝜑 → (𝐵 + 𝐵) ∈ ℂ) |
| 82 | 11, 10 | addcld 10059 |
. . . . . . . . . . 11
⊢ (𝜑 → (𝐴 + 𝐵) ∈ ℂ) |
| 83 | 81, 82, 72, 74 | divsubdird 10840 |
. . . . . . . . . 10
⊢ (𝜑 → (((𝐵 + 𝐵) − (𝐴 + 𝐵)) / 2) = (((𝐵 + 𝐵) / 2) − ((𝐴 + 𝐵) / 2))) |
| 84 | 10, 11, 10 | pnpcan2d 10430 |
. . . . . . . . . . 11
⊢ (𝜑 → ((𝐵 + 𝐵) − (𝐴 + 𝐵)) = (𝐵 − 𝐴)) |
| 85 | 84 | oveq1d 6665 |
. . . . . . . . . 10
⊢ (𝜑 → (((𝐵 + 𝐵) − (𝐴 + 𝐵)) / 2) = ((𝐵 − 𝐴) / 2)) |
| 86 | 80, 83, 85 | 3eqtr2d 2662 |
. . . . . . . . 9
⊢ (𝜑 → (𝐵 − 𝑀) = ((𝐵 − 𝐴) / 2)) |
| 87 | 12, 72, 74 | divrec2d 10805 |
. . . . . . . . 9
⊢ (𝜑 → ((𝐵 − 𝐴) / 2) = ((1 / 2) · (𝐵 − 𝐴))) |
| 88 | 86, 87 | eqtrd 2656 |
. . . . . . . 8
⊢ (𝜑 → (𝐵 − 𝑀) = ((1 / 2) · (𝐵 − 𝐴))) |
| 89 | 88 | fveq2d 6195 |
. . . . . . 7
⊢ (𝜑 → (abs‘(𝐵 − 𝑀)) = (abs‘((1 / 2) · (𝐵 − 𝐴)))) |
| 90 | 40, 12 | absmuld 14193 |
. . . . . . 7
⊢ (𝜑 → (abs‘((1 / 2)
· (𝐵 − 𝐴))) = ((abs‘(1 / 2))
· (abs‘(𝐵
− 𝐴)))) |
| 91 | 59 | a1i 11 |
. . . . . . . . . 10
⊢ (𝜑 → 0 ∈
ℝ) |
| 92 | | halfgt0 11248 |
. . . . . . . . . . 11
⊢ 0 < (1
/ 2) |
| 93 | 92 | a1i 11 |
. . . . . . . . . 10
⊢ (𝜑 → 0 < (1 /
2)) |
| 94 | 91, 42, 93 | ltled 10185 |
. . . . . . . . 9
⊢ (𝜑 → 0 ≤ (1 /
2)) |
| 95 | 42, 94 | absidd 14161 |
. . . . . . . 8
⊢ (𝜑 → (abs‘(1 / 2)) = (1 /
2)) |
| 96 | 95 | oveq1d 6665 |
. . . . . . 7
⊢ (𝜑 → ((abs‘(1 / 2))
· (abs‘(𝐵
− 𝐴))) = ((1 / 2)
· (abs‘(𝐵
− 𝐴)))) |
| 97 | 89, 90, 96 | 3eqtrd 2660 |
. . . . . 6
⊢ (𝜑 → (abs‘(𝐵 − 𝑀)) = ((1 / 2) · (abs‘(𝐵 − 𝐴)))) |
| 98 | 97 | oveq1d 6665 |
. . . . 5
⊢ (𝜑 → ((abs‘(𝐵 − 𝑀))↑2) = (((1 / 2) ·
(abs‘(𝐵 − 𝐴)))↑2)) |
| 99 | 40, 14 | sqmuld 13020 |
. . . . 5
⊢ (𝜑 → (((1 / 2) ·
(abs‘(𝐵 − 𝐴)))↑2) = (((1 / 2)↑2)
· ((abs‘(𝐵
− 𝐴))↑2))) |
| 100 | 98, 99 | eqtrd 2656 |
. . . 4
⊢ (𝜑 → ((abs‘(𝐵 − 𝑀))↑2) = (((1 / 2)↑2) ·
((abs‘(𝐵 −
𝐴))↑2))) |
| 101 | 40, 15, 12 | subdird 10487 |
. . . . . . . . 9
⊢ (𝜑 → (((1 / 2) − 𝑋) · (𝐵 − 𝐴)) = (((1 / 2) · (𝐵 − 𝐴)) − (𝑋 · (𝐵 − 𝐴)))) |
| 102 | 88, 31 | oveq12d 6668 |
. . . . . . . . 9
⊢ (𝜑 → ((𝐵 − 𝑀) − (𝐵 − 𝑃)) = (((1 / 2) · (𝐵 − 𝐴)) − (𝑋 · (𝐵 − 𝐴)))) |
| 103 | 82 | halfcld 11277 |
. . . . . . . . . . 11
⊢ (𝜑 → ((𝐴 + 𝐵) / 2) ∈ ℂ) |
| 104 | 79, 103 | eqeltrd 2701 |
. . . . . . . . . 10
⊢ (𝜑 → 𝑀 ∈ ℂ) |
| 105 | 10, 104, 23 | nnncan1d 10426 |
. . . . . . . . 9
⊢ (𝜑 → ((𝐵 − 𝑀) − (𝐵 − 𝑃)) = (𝑃 − 𝑀)) |
| 106 | 101, 102,
105 | 3eqtr2rd 2663 |
. . . . . . . 8
⊢ (𝜑 → (𝑃 − 𝑀) = (((1 / 2) − 𝑋) · (𝐵 − 𝐴))) |
| 107 | 106 | fveq2d 6195 |
. . . . . . 7
⊢ (𝜑 → (abs‘(𝑃 − 𝑀)) = (abs‘(((1 / 2) − 𝑋) · (𝐵 − 𝐴)))) |
| 108 | 44, 12 | absmuld 14193 |
. . . . . . 7
⊢ (𝜑 → (abs‘(((1 / 2)
− 𝑋) · (𝐵 − 𝐴))) = ((abs‘((1 / 2) − 𝑋)) · (abs‘(𝐵 − 𝐴)))) |
| 109 | 107, 108 | eqtrd 2656 |
. . . . . 6
⊢ (𝜑 → (abs‘(𝑃 − 𝑀)) = ((abs‘((1 / 2) − 𝑋)) · (abs‘(𝐵 − 𝐴)))) |
| 110 | 109 | oveq1d 6665 |
. . . . 5
⊢ (𝜑 → ((abs‘(𝑃 − 𝑀))↑2) = (((abs‘((1 / 2) −
𝑋)) ·
(abs‘(𝐵 − 𝐴)))↑2)) |
| 111 | 46, 14 | sqmuld 13020 |
. . . . 5
⊢ (𝜑 → (((abs‘((1 / 2)
− 𝑋)) ·
(abs‘(𝐵 − 𝐴)))↑2) = (((abs‘((1 /
2) − 𝑋))↑2)
· ((abs‘(𝐵
− 𝐴))↑2))) |
| 112 | 110, 111 | eqtrd 2656 |
. . . 4
⊢ (𝜑 → ((abs‘(𝑃 − 𝑀))↑2) = (((abs‘((1 / 2) −
𝑋))↑2) ·
((abs‘(𝐵 −
𝐴))↑2))) |
| 113 | 100, 112 | oveq12d 6668 |
. . 3
⊢ (𝜑 → (((abs‘(𝐵 − 𝑀))↑2) − ((abs‘(𝑃 − 𝑀))↑2)) = ((((1 / 2)↑2) ·
((abs‘(𝐵 −
𝐴))↑2)) −
(((abs‘((1 / 2) − 𝑋))↑2) · ((abs‘(𝐵 − 𝐴))↑2)))) |
| 114 | 49, 71, 113 | 3eqtr4rd 2667 |
. 2
⊢ (𝜑 → (((abs‘(𝐵 − 𝑀))↑2) − ((abs‘(𝑃 − 𝑀))↑2)) = (((abs‘(1 − 𝑋)) · (abs‘𝑋)) · ((abs‘(𝐵 − 𝐴))↑2))) |
| 115 | 38, 114 | eqtr4d 2659 |
1
⊢ (𝜑 → ((abs‘(𝑃 − 𝐴)) · (abs‘(𝑃 − 𝐵))) = (((abs‘(𝐵 − 𝑀))↑2) − ((abs‘(𝑃 − 𝑀))↑2))) |