Step | Hyp | Ref
| Expression |
1 | | arearect.7 |
. . . . 5
⊢ 𝑆 = ((𝐴[,]𝐵) × (𝐶[,]𝐷)) |
2 | | arearect.1 |
. . . . . . 7
⊢ 𝐴 ∈ ℝ |
3 | | arearect.2 |
. . . . . . 7
⊢ 𝐵 ∈ ℝ |
4 | | iccssre 13090 |
. . . . . . 7
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴[,]𝐵) ⊆ ℝ) |
5 | 2, 3, 4 | mp2an 688 |
. . . . . 6
⊢ (𝐴[,]𝐵) ⊆ ℝ |
6 | | arearect.3 |
. . . . . . 7
⊢ 𝐶 ∈ ℝ |
7 | | arearect.4 |
. . . . . . 7
⊢ 𝐷 ∈ ℝ |
8 | | iccssre 13090 |
. . . . . . 7
⊢ ((𝐶 ∈ ℝ ∧ 𝐷 ∈ ℝ) → (𝐶[,]𝐷) ⊆ ℝ) |
9 | 6, 7, 8 | mp2an 688 |
. . . . . 6
⊢ (𝐶[,]𝐷) ⊆ ℝ |
10 | | xpss12 5595 |
. . . . . 6
⊢ (((𝐴[,]𝐵) ⊆ ℝ ∧ (𝐶[,]𝐷) ⊆ ℝ) → ((𝐴[,]𝐵) × (𝐶[,]𝐷)) ⊆ (ℝ ×
ℝ)) |
11 | 5, 9, 10 | mp2an 688 |
. . . . 5
⊢ ((𝐴[,]𝐵) × (𝐶[,]𝐷)) ⊆ (ℝ ×
ℝ) |
12 | 1, 11 | eqsstri 3951 |
. . . 4
⊢ 𝑆 ⊆ (ℝ ×
ℝ) |
13 | | iftrue 4462 |
. . . . . . . . . . 11
⊢ (𝑥 ∈ (𝐴[,]𝐵) → if(𝑥 ∈ (𝐴[,]𝐵), (𝐷 − 𝐶), 0) = (𝐷 − 𝐶)) |
14 | 1 | imaeq1i 5955 |
. . . . . . . . . . . . . . 15
⊢ (𝑆 “ {𝑥}) = (((𝐴[,]𝐵) × (𝐶[,]𝐷)) “ {𝑥}) |
15 | | iftrue 4462 |
. . . . . . . . . . . . . . . . 17
⊢ (𝑥 ∈ (𝐴[,]𝐵) → if(𝑥 ∈ (𝐴[,]𝐵), (𝐶[,]𝐷), ∅) = (𝐶[,]𝐷)) |
16 | | xpimasn 6077 |
. . . . . . . . . . . . . . . . 17
⊢ (𝑥 ∈ (𝐴[,]𝐵) → (((𝐴[,]𝐵) × (𝐶[,]𝐷)) “ {𝑥}) = (𝐶[,]𝐷)) |
17 | 15, 16 | eqtr4d 2781 |
. . . . . . . . . . . . . . . 16
⊢ (𝑥 ∈ (𝐴[,]𝐵) → if(𝑥 ∈ (𝐴[,]𝐵), (𝐶[,]𝐷), ∅) = (((𝐴[,]𝐵) × (𝐶[,]𝐷)) “ {𝑥})) |
18 | | iffalse 4465 |
. . . . . . . . . . . . . . . . 17
⊢ (¬
𝑥 ∈ (𝐴[,]𝐵) → if(𝑥 ∈ (𝐴[,]𝐵), (𝐶[,]𝐷), ∅) = ∅) |
19 | | disjsn 4644 |
. . . . . . . . . . . . . . . . . 18
⊢ (((𝐴[,]𝐵) ∩ {𝑥}) = ∅ ↔ ¬ 𝑥 ∈ (𝐴[,]𝐵)) |
20 | | xpima1 6075 |
. . . . . . . . . . . . . . . . . 18
⊢ (((𝐴[,]𝐵) ∩ {𝑥}) = ∅ → (((𝐴[,]𝐵) × (𝐶[,]𝐷)) “ {𝑥}) = ∅) |
21 | 19, 20 | sylbir 234 |
. . . . . . . . . . . . . . . . 17
⊢ (¬
𝑥 ∈ (𝐴[,]𝐵) → (((𝐴[,]𝐵) × (𝐶[,]𝐷)) “ {𝑥}) = ∅) |
22 | 18, 21 | eqtr4d 2781 |
. . . . . . . . . . . . . . . 16
⊢ (¬
𝑥 ∈ (𝐴[,]𝐵) → if(𝑥 ∈ (𝐴[,]𝐵), (𝐶[,]𝐷), ∅) = (((𝐴[,]𝐵) × (𝐶[,]𝐷)) “ {𝑥})) |
23 | 17, 22 | pm2.61i 182 |
. . . . . . . . . . . . . . 15
⊢ if(𝑥 ∈ (𝐴[,]𝐵), (𝐶[,]𝐷), ∅) = (((𝐴[,]𝐵) × (𝐶[,]𝐷)) “ {𝑥}) |
24 | 14, 23 | eqtr4i 2769 |
. . . . . . . . . . . . . 14
⊢ (𝑆 “ {𝑥}) = if(𝑥 ∈ (𝐴[,]𝐵), (𝐶[,]𝐷), ∅) |
25 | 24 | fveq2i 6759 |
. . . . . . . . . . . . 13
⊢
(vol‘(𝑆
“ {𝑥})) =
(vol‘if(𝑥 ∈
(𝐴[,]𝐵), (𝐶[,]𝐷), ∅)) |
26 | 15 | fveq2d 6760 |
. . . . . . . . . . . . 13
⊢ (𝑥 ∈ (𝐴[,]𝐵) → (vol‘if(𝑥 ∈ (𝐴[,]𝐵), (𝐶[,]𝐷), ∅)) = (vol‘(𝐶[,]𝐷))) |
27 | 25, 26 | syl5eq 2791 |
. . . . . . . . . . . 12
⊢ (𝑥 ∈ (𝐴[,]𝐵) → (vol‘(𝑆 “ {𝑥})) = (vol‘(𝐶[,]𝐷))) |
28 | | iccmbl 24635 |
. . . . . . . . . . . . . . 15
⊢ ((𝐶 ∈ ℝ ∧ 𝐷 ∈ ℝ) → (𝐶[,]𝐷) ∈ dom vol) |
29 | 6, 7, 28 | mp2an 688 |
. . . . . . . . . . . . . 14
⊢ (𝐶[,]𝐷) ∈ dom vol |
30 | | mblvol 24599 |
. . . . . . . . . . . . . 14
⊢ ((𝐶[,]𝐷) ∈ dom vol → (vol‘(𝐶[,]𝐷)) = (vol*‘(𝐶[,]𝐷))) |
31 | 29, 30 | ax-mp 5 |
. . . . . . . . . . . . 13
⊢
(vol‘(𝐶[,]𝐷)) = (vol*‘(𝐶[,]𝐷)) |
32 | | arearect.6 |
. . . . . . . . . . . . . 14
⊢ 𝐶 ≤ 𝐷 |
33 | | ovolicc 24592 |
. . . . . . . . . . . . . 14
⊢ ((𝐶 ∈ ℝ ∧ 𝐷 ∈ ℝ ∧ 𝐶 ≤ 𝐷) → (vol*‘(𝐶[,]𝐷)) = (𝐷 − 𝐶)) |
34 | 6, 7, 32, 33 | mp3an 1459 |
. . . . . . . . . . . . 13
⊢
(vol*‘(𝐶[,]𝐷)) = (𝐷 − 𝐶) |
35 | 31, 34 | eqtri 2766 |
. . . . . . . . . . . 12
⊢
(vol‘(𝐶[,]𝐷)) = (𝐷 − 𝐶) |
36 | 27, 35 | eqtrdi 2795 |
. . . . . . . . . . 11
⊢ (𝑥 ∈ (𝐴[,]𝐵) → (vol‘(𝑆 “ {𝑥})) = (𝐷 − 𝐶)) |
37 | 13, 36 | eqtr4d 2781 |
. . . . . . . . . 10
⊢ (𝑥 ∈ (𝐴[,]𝐵) → if(𝑥 ∈ (𝐴[,]𝐵), (𝐷 − 𝐶), 0) = (vol‘(𝑆 “ {𝑥}))) |
38 | | iffalse 4465 |
. . . . . . . . . . 11
⊢ (¬
𝑥 ∈ (𝐴[,]𝐵) → if(𝑥 ∈ (𝐴[,]𝐵), (𝐷 − 𝐶), 0) = 0) |
39 | 18 | fveq2d 6760 |
. . . . . . . . . . . . 13
⊢ (¬
𝑥 ∈ (𝐴[,]𝐵) → (vol‘if(𝑥 ∈ (𝐴[,]𝐵), (𝐶[,]𝐷), ∅)) =
(vol‘∅)) |
40 | 25, 39 | syl5eq 2791 |
. . . . . . . . . . . 12
⊢ (¬
𝑥 ∈ (𝐴[,]𝐵) → (vol‘(𝑆 “ {𝑥})) = (vol‘∅)) |
41 | | 0mbl 24608 |
. . . . . . . . . . . . . 14
⊢ ∅
∈ dom vol |
42 | | mblvol 24599 |
. . . . . . . . . . . . . 14
⊢ (∅
∈ dom vol → (vol‘∅) =
(vol*‘∅)) |
43 | 41, 42 | ax-mp 5 |
. . . . . . . . . . . . 13
⊢
(vol‘∅) = (vol*‘∅) |
44 | | ovol0 24562 |
. . . . . . . . . . . . 13
⊢
(vol*‘∅) = 0 |
45 | 43, 44 | eqtri 2766 |
. . . . . . . . . . . 12
⊢
(vol‘∅) = 0 |
46 | 40, 45 | eqtrdi 2795 |
. . . . . . . . . . 11
⊢ (¬
𝑥 ∈ (𝐴[,]𝐵) → (vol‘(𝑆 “ {𝑥})) = 0) |
47 | 38, 46 | eqtr4d 2781 |
. . . . . . . . . 10
⊢ (¬
𝑥 ∈ (𝐴[,]𝐵) → if(𝑥 ∈ (𝐴[,]𝐵), (𝐷 − 𝐶), 0) = (vol‘(𝑆 “ {𝑥}))) |
48 | 37, 47 | pm2.61i 182 |
. . . . . . . . 9
⊢ if(𝑥 ∈ (𝐴[,]𝐵), (𝐷 − 𝐶), 0) = (vol‘(𝑆 “ {𝑥})) |
49 | 48 | eqcomi 2747 |
. . . . . . . 8
⊢
(vol‘(𝑆
“ {𝑥})) = if(𝑥 ∈ (𝐴[,]𝐵), (𝐷 − 𝐶), 0) |
50 | 49 | a1i 11 |
. . . . . . 7
⊢ (𝑥 ∈ ℝ →
(vol‘(𝑆 “
{𝑥})) = if(𝑥 ∈ (𝐴[,]𝐵), (𝐷 − 𝐶), 0)) |
51 | 7, 6 | resubcli 11213 |
. . . . . . . 8
⊢ (𝐷 − 𝐶) ∈ ℝ |
52 | | 0re 10908 |
. . . . . . . 8
⊢ 0 ∈
ℝ |
53 | 51, 52 | ifcli 4503 |
. . . . . . 7
⊢ if(𝑥 ∈ (𝐴[,]𝐵), (𝐷 − 𝐶), 0) ∈ ℝ |
54 | 50, 53 | eqeltrdi 2847 |
. . . . . 6
⊢ (𝑥 ∈ ℝ →
(vol‘(𝑆 “
{𝑥})) ∈
ℝ) |
55 | | volf 24598 |
. . . . . . . 8
⊢ vol:dom
vol⟶(0[,]+∞) |
56 | | ffun 6587 |
. . . . . . . 8
⊢ (vol:dom
vol⟶(0[,]+∞) → Fun vol) |
57 | 55, 56 | ax-mp 5 |
. . . . . . 7
⊢ Fun
vol |
58 | 29, 41 | ifcli 4503 |
. . . . . . . 8
⊢ if(𝑥 ∈ (𝐴[,]𝐵), (𝐶[,]𝐷), ∅) ∈ dom vol |
59 | 24, 58 | eqeltri 2835 |
. . . . . . 7
⊢ (𝑆 “ {𝑥}) ∈ dom vol |
60 | | fvimacnv 6912 |
. . . . . . 7
⊢ ((Fun vol
∧ (𝑆 “ {𝑥}) ∈ dom vol) →
((vol‘(𝑆 “
{𝑥})) ∈ ℝ ↔
(𝑆 “ {𝑥}) ∈ (◡vol “ ℝ))) |
61 | 57, 59, 60 | mp2an 688 |
. . . . . 6
⊢
((vol‘(𝑆
“ {𝑥})) ∈
ℝ ↔ (𝑆 “
{𝑥}) ∈ (◡vol “ ℝ)) |
62 | 54, 61 | sylib 217 |
. . . . 5
⊢ (𝑥 ∈ ℝ → (𝑆 “ {𝑥}) ∈ (◡vol “ ℝ)) |
63 | 62 | rgen 3073 |
. . . 4
⊢
∀𝑥 ∈
ℝ (𝑆 “ {𝑥}) ∈ (◡vol “ ℝ) |
64 | 5 | a1i 11 |
. . . . . 6
⊢ (0 ∈
ℝ → (𝐴[,]𝐵) ⊆
ℝ) |
65 | | rembl 24609 |
. . . . . . 7
⊢ ℝ
∈ dom vol |
66 | 65 | a1i 11 |
. . . . . 6
⊢ (0 ∈
ℝ → ℝ ∈ dom vol) |
67 | 36, 51 | eqeltrdi 2847 |
. . . . . . 7
⊢ (𝑥 ∈ (𝐴[,]𝐵) → (vol‘(𝑆 “ {𝑥})) ∈ ℝ) |
68 | 67 | adantl 481 |
. . . . . 6
⊢ ((0
∈ ℝ ∧ 𝑥
∈ (𝐴[,]𝐵)) → (vol‘(𝑆 “ {𝑥})) ∈ ℝ) |
69 | | eldifn 4058 |
. . . . . . . 8
⊢ (𝑥 ∈ (ℝ ∖ (𝐴[,]𝐵)) → ¬ 𝑥 ∈ (𝐴[,]𝐵)) |
70 | 69, 46 | syl 17 |
. . . . . . 7
⊢ (𝑥 ∈ (ℝ ∖ (𝐴[,]𝐵)) → (vol‘(𝑆 “ {𝑥})) = 0) |
71 | 70 | adantl 481 |
. . . . . 6
⊢ ((0
∈ ℝ ∧ 𝑥
∈ (ℝ ∖ (𝐴[,]𝐵))) → (vol‘(𝑆 “ {𝑥})) = 0) |
72 | 36 | mpteq2ia 5173 |
. . . . . . . 8
⊢ (𝑥 ∈ (𝐴[,]𝐵) ↦ (vol‘(𝑆 “ {𝑥}))) = (𝑥 ∈ (𝐴[,]𝐵) ↦ (𝐷 − 𝐶)) |
73 | 51 | recni 10920 |
. . . . . . . . . 10
⊢ (𝐷 − 𝐶) ∈ ℂ |
74 | | ax-resscn 10859 |
. . . . . . . . . . 11
⊢ ℝ
⊆ ℂ |
75 | 5, 74 | sstri 3926 |
. . . . . . . . . 10
⊢ (𝐴[,]𝐵) ⊆ ℂ |
76 | | ssid 3939 |
. . . . . . . . . 10
⊢ ℂ
⊆ ℂ |
77 | | cncfmptc 23981 |
. . . . . . . . . 10
⊢ (((𝐷 − 𝐶) ∈ ℂ ∧ (𝐴[,]𝐵) ⊆ ℂ ∧ ℂ ⊆
ℂ) → (𝑥 ∈
(𝐴[,]𝐵) ↦ (𝐷 − 𝐶)) ∈ ((𝐴[,]𝐵)–cn→ℂ)) |
78 | 73, 75, 76, 77 | mp3an 1459 |
. . . . . . . . 9
⊢ (𝑥 ∈ (𝐴[,]𝐵) ↦ (𝐷 − 𝐶)) ∈ ((𝐴[,]𝐵)–cn→ℂ) |
79 | | cniccibl 24910 |
. . . . . . . . 9
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ (𝑥 ∈ (𝐴[,]𝐵) ↦ (𝐷 − 𝐶)) ∈ ((𝐴[,]𝐵)–cn→ℂ)) → (𝑥 ∈ (𝐴[,]𝐵) ↦ (𝐷 − 𝐶)) ∈
𝐿1) |
80 | 2, 3, 78, 79 | mp3an 1459 |
. . . . . . . 8
⊢ (𝑥 ∈ (𝐴[,]𝐵) ↦ (𝐷 − 𝐶)) ∈
𝐿1 |
81 | 72, 80 | eqeltri 2835 |
. . . . . . 7
⊢ (𝑥 ∈ (𝐴[,]𝐵) ↦ (vol‘(𝑆 “ {𝑥}))) ∈
𝐿1 |
82 | 81 | a1i 11 |
. . . . . 6
⊢ (0 ∈
ℝ → (𝑥 ∈
(𝐴[,]𝐵) ↦ (vol‘(𝑆 “ {𝑥}))) ∈
𝐿1) |
83 | 64, 66, 68, 71, 82 | iblss2 24875 |
. . . . 5
⊢ (0 ∈
ℝ → (𝑥 ∈
ℝ ↦ (vol‘(𝑆 “ {𝑥}))) ∈
𝐿1) |
84 | 52, 83 | ax-mp 5 |
. . . 4
⊢ (𝑥 ∈ ℝ ↦
(vol‘(𝑆 “
{𝑥}))) ∈
𝐿1 |
85 | | dmarea 26012 |
. . . 4
⊢ (𝑆 ∈ dom area ↔ (𝑆 ⊆ (ℝ ×
ℝ) ∧ ∀𝑥
∈ ℝ (𝑆 “
{𝑥}) ∈ (◡vol “ ℝ) ∧ (𝑥 ∈ ℝ ↦
(vol‘(𝑆 “
{𝑥}))) ∈
𝐿1)) |
86 | 12, 63, 84, 85 | mpbir3an 1339 |
. . 3
⊢ 𝑆 ∈ dom
area |
87 | | areaval 26019 |
. . 3
⊢ (𝑆 ∈ dom area →
(area‘𝑆) =
∫ℝ(vol‘(𝑆
“ {𝑥})) d𝑥) |
88 | 86, 87 | ax-mp 5 |
. 2
⊢
(area‘𝑆) =
∫ℝ(vol‘(𝑆
“ {𝑥})) d𝑥 |
89 | | itgeq2 24847 |
. . . 4
⊢
(∀𝑥 ∈
ℝ (vol‘(𝑆
“ {𝑥})) = if(𝑥 ∈ (𝐴[,]𝐵), (𝐷 − 𝐶), 0) → ∫ℝ(vol‘(𝑆 “ {𝑥})) d𝑥 = ∫ℝif(𝑥 ∈ (𝐴[,]𝐵), (𝐷 − 𝐶), 0) d𝑥) |
90 | 89, 50 | mprg 3077 |
. . 3
⊢
∫ℝ(vol‘(𝑆 “ {𝑥})) d𝑥 = ∫ℝif(𝑥 ∈ (𝐴[,]𝐵), (𝐷 − 𝐶), 0) d𝑥 |
91 | | iccmbl 24635 |
. . . . . 6
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴[,]𝐵) ∈ dom vol) |
92 | 2, 3, 91 | mp2an 688 |
. . . . 5
⊢ (𝐴[,]𝐵) ∈ dom vol |
93 | | mblvol 24599 |
. . . . . . . 8
⊢ ((𝐴[,]𝐵) ∈ dom vol → (vol‘(𝐴[,]𝐵)) = (vol*‘(𝐴[,]𝐵))) |
94 | 92, 93 | ax-mp 5 |
. . . . . . 7
⊢
(vol‘(𝐴[,]𝐵)) = (vol*‘(𝐴[,]𝐵)) |
95 | | arearect.5 |
. . . . . . . 8
⊢ 𝐴 ≤ 𝐵 |
96 | | ovolicc 24592 |
. . . . . . . 8
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐴 ≤ 𝐵) → (vol*‘(𝐴[,]𝐵)) = (𝐵 − 𝐴)) |
97 | 2, 3, 95, 96 | mp3an 1459 |
. . . . . . 7
⊢
(vol*‘(𝐴[,]𝐵)) = (𝐵 − 𝐴) |
98 | 94, 97 | eqtri 2766 |
. . . . . 6
⊢
(vol‘(𝐴[,]𝐵)) = (𝐵 − 𝐴) |
99 | 3, 2 | resubcli 11213 |
. . . . . 6
⊢ (𝐵 − 𝐴) ∈ ℝ |
100 | 98, 99 | eqeltri 2835 |
. . . . 5
⊢
(vol‘(𝐴[,]𝐵)) ∈ ℝ |
101 | | itgconst 24888 |
. . . . 5
⊢ (((𝐴[,]𝐵) ∈ dom vol ∧ (vol‘(𝐴[,]𝐵)) ∈ ℝ ∧ (𝐷 − 𝐶) ∈ ℂ) → ∫(𝐴[,]𝐵)(𝐷 − 𝐶) d𝑥 = ((𝐷 − 𝐶) · (vol‘(𝐴[,]𝐵)))) |
102 | 92, 100, 73, 101 | mp3an 1459 |
. . . 4
⊢
∫(𝐴[,]𝐵)(𝐷 − 𝐶) d𝑥 = ((𝐷 − 𝐶) · (vol‘(𝐴[,]𝐵))) |
103 | | itgss2 24882 |
. . . . 5
⊢ ((𝐴[,]𝐵) ⊆ ℝ → ∫(𝐴[,]𝐵)(𝐷 − 𝐶) d𝑥 = ∫ℝif(𝑥 ∈ (𝐴[,]𝐵), (𝐷 − 𝐶), 0) d𝑥) |
104 | 5, 103 | ax-mp 5 |
. . . 4
⊢
∫(𝐴[,]𝐵)(𝐷 − 𝐶) d𝑥 = ∫ℝif(𝑥 ∈ (𝐴[,]𝐵), (𝐷 − 𝐶), 0) d𝑥 |
105 | 98 | oveq2i 7266 |
. . . 4
⊢ ((𝐷 − 𝐶) · (vol‘(𝐴[,]𝐵))) = ((𝐷 − 𝐶) · (𝐵 − 𝐴)) |
106 | 102, 104,
105 | 3eqtr3i 2774 |
. . 3
⊢
∫ℝif(𝑥
∈ (𝐴[,]𝐵), (𝐷 − 𝐶), 0) d𝑥 = ((𝐷 − 𝐶) · (𝐵 − 𝐴)) |
107 | 90, 106 | eqtri 2766 |
. 2
⊢
∫ℝ(vol‘(𝑆 “ {𝑥})) d𝑥 = ((𝐷 − 𝐶) · (𝐵 − 𝐴)) |
108 | 99 | recni 10920 |
. . 3
⊢ (𝐵 − 𝐴) ∈ ℂ |
109 | 73, 108 | mulcomi 10914 |
. 2
⊢ ((𝐷 − 𝐶) · (𝐵 − 𝐴)) = ((𝐵 − 𝐴) · (𝐷 − 𝐶)) |
110 | 88, 107, 109 | 3eqtri 2770 |
1
⊢
(area‘𝑆) =
((𝐵 − 𝐴) · (𝐷 − 𝐶)) |