Proof of Theorem itgitg1
| Step | Hyp | Ref
| Expression |
| 1 | | i1ff 25712 |
. . . 4
⊢ (𝐹 ∈ dom ∫1
→ 𝐹:ℝ⟶ℝ) |
| 2 | 1 | ffvelcdmda 7103 |
. . 3
⊢ ((𝐹 ∈ dom ∫1
∧ 𝑥 ∈ ℝ)
→ (𝐹‘𝑥) ∈
ℝ) |
| 3 | 1 | feqmptd 6976 |
. . . 4
⊢ (𝐹 ∈ dom ∫1
→ 𝐹 = (𝑥 ∈ ℝ ↦ (𝐹‘𝑥))) |
| 4 | | i1fibl 25844 |
. . . 4
⊢ (𝐹 ∈ dom ∫1
→ 𝐹 ∈
𝐿1) |
| 5 | 3, 4 | eqeltrrd 2841 |
. . 3
⊢ (𝐹 ∈ dom ∫1
→ (𝑥 ∈ ℝ
↦ (𝐹‘𝑥)) ∈
𝐿1) |
| 6 | 2, 5 | itgreval 25833 |
. 2
⊢ (𝐹 ∈ dom ∫1
→ ∫ℝ(𝐹‘𝑥) d𝑥 = (∫ℝif(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0) d𝑥 − ∫ℝif(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0) d𝑥)) |
| 7 | | 0re 11264 |
. . . . . . 7
⊢ 0 ∈
ℝ |
| 8 | | ifcl 4570 |
. . . . . . 7
⊢ (((𝐹‘𝑥) ∈ ℝ ∧ 0 ∈ ℝ)
→ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0) ∈ ℝ) |
| 9 | 2, 7, 8 | sylancl 586 |
. . . . . 6
⊢ ((𝐹 ∈ dom ∫1
∧ 𝑥 ∈ ℝ)
→ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0) ∈ ℝ) |
| 10 | | max1 13228 |
. . . . . . 7
⊢ ((0
∈ ℝ ∧ (𝐹‘𝑥) ∈ ℝ) → 0 ≤ if(0 ≤
(𝐹‘𝑥), (𝐹‘𝑥), 0)) |
| 11 | 7, 2, 10 | sylancr 587 |
. . . . . 6
⊢ ((𝐹 ∈ dom ∫1
∧ 𝑥 ∈ ℝ)
→ 0 ≤ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)) |
| 12 | | id 22 |
. . . . . . . . 9
⊢ (𝐹 ∈ dom ∫1
→ 𝐹 ∈ dom
∫1) |
| 13 | 3, 12 | eqeltrrd 2841 |
. . . . . . . 8
⊢ (𝐹 ∈ dom ∫1
→ (𝑥 ∈ ℝ
↦ (𝐹‘𝑥)) ∈ dom
∫1) |
| 14 | 13 | i1fposd 25743 |
. . . . . . 7
⊢ (𝐹 ∈ dom ∫1
→ (𝑥 ∈ ℝ
↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)) ∈ dom
∫1) |
| 15 | | i1fibl 25844 |
. . . . . . 7
⊢ ((𝑥 ∈ ℝ ↦ if(0
≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)) ∈ dom ∫1 →
(𝑥 ∈ ℝ ↦
if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)) ∈
𝐿1) |
| 16 | 14, 15 | syl 17 |
. . . . . 6
⊢ (𝐹 ∈ dom ∫1
→ (𝑥 ∈ ℝ
↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)) ∈
𝐿1) |
| 17 | 9, 11, 16 | itgitg2 25843 |
. . . . 5
⊢ (𝐹 ∈ dom ∫1
→ ∫ℝif(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0) d𝑥 = (∫2‘(𝑥 ∈ ℝ ↦ if(0
≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)))) |
| 18 | 11 | ralrimiva 3145 |
. . . . . . . 8
⊢ (𝐹 ∈ dom ∫1
→ ∀𝑥 ∈
ℝ 0 ≤ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)) |
| 19 | | reex 11247 |
. . . . . . . . . 10
⊢ ℝ
∈ V |
| 20 | 19 | a1i 11 |
. . . . . . . . 9
⊢ (𝐹 ∈ dom ∫1
→ ℝ ∈ V) |
| 21 | 7 | a1i 11 |
. . . . . . . . 9
⊢ ((𝐹 ∈ dom ∫1
∧ 𝑥 ∈ ℝ)
→ 0 ∈ ℝ) |
| 22 | | fconstmpt 5746 |
. . . . . . . . . 10
⊢ (ℝ
× {0}) = (𝑥 ∈
ℝ ↦ 0) |
| 23 | 22 | a1i 11 |
. . . . . . . . 9
⊢ (𝐹 ∈ dom ∫1
→ (ℝ × {0}) = (𝑥 ∈ ℝ ↦ 0)) |
| 24 | | eqidd 2737 |
. . . . . . . . 9
⊢ (𝐹 ∈ dom ∫1
→ (𝑥 ∈ ℝ
↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)) = (𝑥 ∈ ℝ ↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0))) |
| 25 | 20, 21, 9, 23, 24 | ofrfval2 7719 |
. . . . . . . 8
⊢ (𝐹 ∈ dom ∫1
→ ((ℝ × {0}) ∘r ≤ (𝑥 ∈ ℝ ↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)) ↔ ∀𝑥 ∈ ℝ 0 ≤ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0))) |
| 26 | 18, 25 | mpbird 257 |
. . . . . . 7
⊢ (𝐹 ∈ dom ∫1
→ (ℝ × {0}) ∘r ≤ (𝑥 ∈ ℝ ↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0))) |
| 27 | | ax-resscn 11213 |
. . . . . . . . 9
⊢ ℝ
⊆ ℂ |
| 28 | 27 | a1i 11 |
. . . . . . . 8
⊢ (𝐹 ∈ dom ∫1
→ ℝ ⊆ ℂ) |
| 29 | 9 | fmpttd 7134 |
. . . . . . . . 9
⊢ (𝐹 ∈ dom ∫1
→ (𝑥 ∈ ℝ
↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥),
0)):ℝ⟶ℝ) |
| 30 | 29 | ffnd 6736 |
. . . . . . . 8
⊢ (𝐹 ∈ dom ∫1
→ (𝑥 ∈ ℝ
↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)) Fn ℝ) |
| 31 | 28, 30 | 0pledm 25709 |
. . . . . . 7
⊢ (𝐹 ∈ dom ∫1
→ (0𝑝 ∘r ≤ (𝑥 ∈ ℝ ↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)) ↔ (ℝ × {0})
∘r ≤ (𝑥
∈ ℝ ↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)))) |
| 32 | 26, 31 | mpbird 257 |
. . . . . 6
⊢ (𝐹 ∈ dom ∫1
→ 0𝑝 ∘r ≤ (𝑥 ∈ ℝ ↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0))) |
| 33 | | itg2itg1 25772 |
. . . . . 6
⊢ (((𝑥 ∈ ℝ ↦ if(0
≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)) ∈ dom ∫1 ∧
0𝑝 ∘r ≤ (𝑥 ∈ ℝ ↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0))) →
(∫2‘(𝑥
∈ ℝ ↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0))) = (∫1‘(𝑥 ∈ ℝ ↦ if(0
≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)))) |
| 34 | 14, 32, 33 | syl2anc 584 |
. . . . 5
⊢ (𝐹 ∈ dom ∫1
→ (∫2‘(𝑥 ∈ ℝ ↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0))) = (∫1‘(𝑥 ∈ ℝ ↦ if(0
≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)))) |
| 35 | 17, 34 | eqtrd 2776 |
. . . 4
⊢ (𝐹 ∈ dom ∫1
→ ∫ℝif(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0) d𝑥 = (∫1‘(𝑥 ∈ ℝ ↦ if(0
≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)))) |
| 36 | 2 | renegcld 11691 |
. . . . . . 7
⊢ ((𝐹 ∈ dom ∫1
∧ 𝑥 ∈ ℝ)
→ -(𝐹‘𝑥) ∈
ℝ) |
| 37 | | ifcl 4570 |
. . . . . . 7
⊢ ((-(𝐹‘𝑥) ∈ ℝ ∧ 0 ∈ ℝ)
→ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0) ∈ ℝ) |
| 38 | 36, 7, 37 | sylancl 586 |
. . . . . 6
⊢ ((𝐹 ∈ dom ∫1
∧ 𝑥 ∈ ℝ)
→ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0) ∈ ℝ) |
| 39 | | max1 13228 |
. . . . . . 7
⊢ ((0
∈ ℝ ∧ -(𝐹‘𝑥) ∈ ℝ) → 0 ≤ if(0 ≤
-(𝐹‘𝑥), -(𝐹‘𝑥), 0)) |
| 40 | 7, 36, 39 | sylancr 587 |
. . . . . 6
⊢ ((𝐹 ∈ dom ∫1
∧ 𝑥 ∈ ℝ)
→ 0 ≤ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)) |
| 41 | | neg1rr 12382 |
. . . . . . . . . . . 12
⊢ -1 ∈
ℝ |
| 42 | 41 | a1i 11 |
. . . . . . . . . . 11
⊢ ((𝐹 ∈ dom ∫1
∧ 𝑥 ∈ ℝ)
→ -1 ∈ ℝ) |
| 43 | | fconstmpt 5746 |
. . . . . . . . . . . 12
⊢ (ℝ
× {-1}) = (𝑥 ∈
ℝ ↦ -1) |
| 44 | 43 | a1i 11 |
. . . . . . . . . . 11
⊢ (𝐹 ∈ dom ∫1
→ (ℝ × {-1}) = (𝑥 ∈ ℝ ↦ -1)) |
| 45 | 20, 42, 2, 44, 3 | offval2 7718 |
. . . . . . . . . 10
⊢ (𝐹 ∈ dom ∫1
→ ((ℝ × {-1}) ∘f · 𝐹) = (𝑥 ∈ ℝ ↦ (-1 · (𝐹‘𝑥)))) |
| 46 | 2 | recnd 11290 |
. . . . . . . . . . . 12
⊢ ((𝐹 ∈ dom ∫1
∧ 𝑥 ∈ ℝ)
→ (𝐹‘𝑥) ∈
ℂ) |
| 47 | 46 | mulm1d 11716 |
. . . . . . . . . . 11
⊢ ((𝐹 ∈ dom ∫1
∧ 𝑥 ∈ ℝ)
→ (-1 · (𝐹‘𝑥)) = -(𝐹‘𝑥)) |
| 48 | 47 | mpteq2dva 5241 |
. . . . . . . . . 10
⊢ (𝐹 ∈ dom ∫1
→ (𝑥 ∈ ℝ
↦ (-1 · (𝐹‘𝑥))) = (𝑥 ∈ ℝ ↦ -(𝐹‘𝑥))) |
| 49 | 45, 48 | eqtrd 2776 |
. . . . . . . . 9
⊢ (𝐹 ∈ dom ∫1
→ ((ℝ × {-1}) ∘f · 𝐹) = (𝑥 ∈ ℝ ↦ -(𝐹‘𝑥))) |
| 50 | 41 | a1i 11 |
. . . . . . . . . 10
⊢ (𝐹 ∈ dom ∫1
→ -1 ∈ ℝ) |
| 51 | 12, 50 | i1fmulc 25739 |
. . . . . . . . 9
⊢ (𝐹 ∈ dom ∫1
→ ((ℝ × {-1}) ∘f · 𝐹) ∈ dom
∫1) |
| 52 | 49, 51 | eqeltrrd 2841 |
. . . . . . . 8
⊢ (𝐹 ∈ dom ∫1
→ (𝑥 ∈ ℝ
↦ -(𝐹‘𝑥)) ∈ dom
∫1) |
| 53 | 52 | i1fposd 25743 |
. . . . . . 7
⊢ (𝐹 ∈ dom ∫1
→ (𝑥 ∈ ℝ
↦ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)) ∈ dom
∫1) |
| 54 | | i1fibl 25844 |
. . . . . . 7
⊢ ((𝑥 ∈ ℝ ↦ if(0
≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)) ∈ dom ∫1 →
(𝑥 ∈ ℝ ↦
if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)) ∈
𝐿1) |
| 55 | 53, 54 | syl 17 |
. . . . . 6
⊢ (𝐹 ∈ dom ∫1
→ (𝑥 ∈ ℝ
↦ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)) ∈
𝐿1) |
| 56 | 38, 40, 55 | itgitg2 25843 |
. . . . 5
⊢ (𝐹 ∈ dom ∫1
→ ∫ℝif(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0) d𝑥 = (∫2‘(𝑥 ∈ ℝ ↦ if(0
≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)))) |
| 57 | 40 | ralrimiva 3145 |
. . . . . . . 8
⊢ (𝐹 ∈ dom ∫1
→ ∀𝑥 ∈
ℝ 0 ≤ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)) |
| 58 | | eqidd 2737 |
. . . . . . . . 9
⊢ (𝐹 ∈ dom ∫1
→ (𝑥 ∈ ℝ
↦ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)) = (𝑥 ∈ ℝ ↦ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0))) |
| 59 | 20, 21, 38, 23, 58 | ofrfval2 7719 |
. . . . . . . 8
⊢ (𝐹 ∈ dom ∫1
→ ((ℝ × {0}) ∘r ≤ (𝑥 ∈ ℝ ↦ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)) ↔ ∀𝑥 ∈ ℝ 0 ≤ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0))) |
| 60 | 57, 59 | mpbird 257 |
. . . . . . 7
⊢ (𝐹 ∈ dom ∫1
→ (ℝ × {0}) ∘r ≤ (𝑥 ∈ ℝ ↦ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0))) |
| 61 | 38 | fmpttd 7134 |
. . . . . . . . 9
⊢ (𝐹 ∈ dom ∫1
→ (𝑥 ∈ ℝ
↦ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥),
0)):ℝ⟶ℝ) |
| 62 | 61 | ffnd 6736 |
. . . . . . . 8
⊢ (𝐹 ∈ dom ∫1
→ (𝑥 ∈ ℝ
↦ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)) Fn ℝ) |
| 63 | 28, 62 | 0pledm 25709 |
. . . . . . 7
⊢ (𝐹 ∈ dom ∫1
→ (0𝑝 ∘r ≤ (𝑥 ∈ ℝ ↦ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)) ↔ (ℝ × {0})
∘r ≤ (𝑥
∈ ℝ ↦ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)))) |
| 64 | 60, 63 | mpbird 257 |
. . . . . 6
⊢ (𝐹 ∈ dom ∫1
→ 0𝑝 ∘r ≤ (𝑥 ∈ ℝ ↦ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0))) |
| 65 | | itg2itg1 25772 |
. . . . . 6
⊢ (((𝑥 ∈ ℝ ↦ if(0
≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)) ∈ dom ∫1 ∧
0𝑝 ∘r ≤ (𝑥 ∈ ℝ ↦ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0))) →
(∫2‘(𝑥
∈ ℝ ↦ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0))) = (∫1‘(𝑥 ∈ ℝ ↦ if(0
≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)))) |
| 66 | 53, 64, 65 | syl2anc 584 |
. . . . 5
⊢ (𝐹 ∈ dom ∫1
→ (∫2‘(𝑥 ∈ ℝ ↦ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0))) = (∫1‘(𝑥 ∈ ℝ ↦ if(0
≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)))) |
| 67 | 56, 66 | eqtrd 2776 |
. . . 4
⊢ (𝐹 ∈ dom ∫1
→ ∫ℝif(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0) d𝑥 = (∫1‘(𝑥 ∈ ℝ ↦ if(0
≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)))) |
| 68 | 35, 67 | oveq12d 7450 |
. . 3
⊢ (𝐹 ∈ dom ∫1
→ (∫ℝif(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0) d𝑥 − ∫ℝif(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0) d𝑥) = ((∫1‘(𝑥 ∈ ℝ ↦ if(0
≤ (𝐹‘𝑥), (𝐹‘𝑥), 0))) −
(∫1‘(𝑥
∈ ℝ ↦ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0))))) |
| 69 | | itg1sub 25745 |
. . . 4
⊢ (((𝑥 ∈ ℝ ↦ if(0
≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)) ∈ dom ∫1 ∧
(𝑥 ∈ ℝ ↦
if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)) ∈ dom ∫1) →
(∫1‘((𝑥 ∈ ℝ ↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)) ∘f − (𝑥 ∈ ℝ ↦ if(0
≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)))) = ((∫1‘(𝑥 ∈ ℝ ↦ if(0
≤ (𝐹‘𝑥), (𝐹‘𝑥), 0))) −
(∫1‘(𝑥
∈ ℝ ↦ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0))))) |
| 70 | 14, 53, 69 | syl2anc 584 |
. . 3
⊢ (𝐹 ∈ dom ∫1
→ (∫1‘((𝑥 ∈ ℝ ↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)) ∘f − (𝑥 ∈ ℝ ↦ if(0
≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)))) = ((∫1‘(𝑥 ∈ ℝ ↦ if(0
≤ (𝐹‘𝑥), (𝐹‘𝑥), 0))) −
(∫1‘(𝑥
∈ ℝ ↦ if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0))))) |
| 71 | 68, 70 | eqtr4d 2779 |
. 2
⊢ (𝐹 ∈ dom ∫1
→ (∫ℝif(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0) d𝑥 − ∫ℝif(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0) d𝑥) = (∫1‘((𝑥 ∈ ℝ ↦ if(0
≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)) ∘f − (𝑥 ∈ ℝ ↦ if(0
≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0))))) |
| 72 | | max0sub 13239 |
. . . . . 6
⊢ ((𝐹‘𝑥) ∈ ℝ → (if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0) − if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)) = (𝐹‘𝑥)) |
| 73 | 2, 72 | syl 17 |
. . . . 5
⊢ ((𝐹 ∈ dom ∫1
∧ 𝑥 ∈ ℝ)
→ (if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0) − if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)) = (𝐹‘𝑥)) |
| 74 | 73 | mpteq2dva 5241 |
. . . 4
⊢ (𝐹 ∈ dom ∫1
→ (𝑥 ∈ ℝ
↦ (if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0) − if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0))) = (𝑥 ∈ ℝ ↦ (𝐹‘𝑥))) |
| 75 | 20, 9, 38, 24, 58 | offval2 7718 |
. . . 4
⊢ (𝐹 ∈ dom ∫1
→ ((𝑥 ∈ ℝ
↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)) ∘f − (𝑥 ∈ ℝ ↦ if(0
≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0))) = (𝑥 ∈ ℝ ↦ (if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0) − if(0 ≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)))) |
| 76 | 74, 75, 3 | 3eqtr4d 2786 |
. . 3
⊢ (𝐹 ∈ dom ∫1
→ ((𝑥 ∈ ℝ
↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)) ∘f − (𝑥 ∈ ℝ ↦ if(0
≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0))) = 𝐹) |
| 77 | 76 | fveq2d 6909 |
. 2
⊢ (𝐹 ∈ dom ∫1
→ (∫1‘((𝑥 ∈ ℝ ↦ if(0 ≤ (𝐹‘𝑥), (𝐹‘𝑥), 0)) ∘f − (𝑥 ∈ ℝ ↦ if(0
≤ -(𝐹‘𝑥), -(𝐹‘𝑥), 0)))) = (∫1‘𝐹)) |
| 78 | 6, 71, 77 | 3eqtrd 2780 |
1
⊢ (𝐹 ∈ dom ∫1
→ ∫ℝ(𝐹‘𝑥) d𝑥 = (∫1‘𝐹)) |