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BASIC REAL AND COMPLEX ANALYSIS
Integrals
Lebesgue integration
Lesbesgue integral
ibladd
Next ⟩
iblsub
Metamath Proof Explorer
Ascii
Unicode
Theorem
ibladd
Description:
Add two integrals over the same domain.
(Contributed by
Mario Carneiro
, 17-Aug-2014)
Ref
Expression
Hypotheses
itgadd.1
⊢
φ
∧
x
∈
A
→
B
∈
V
itgadd.2
⊢
φ
→
x
∈
A
⟼
B
∈
𝐿
1
itgadd.3
⊢
φ
∧
x
∈
A
→
C
∈
V
itgadd.4
⊢
φ
→
x
∈
A
⟼
C
∈
𝐿
1
Assertion
ibladd
⊢
φ
→
x
∈
A
⟼
B
+
C
∈
𝐿
1
Proof
Step
Hyp
Ref
Expression
1
itgadd.1
⊢
φ
∧
x
∈
A
→
B
∈
V
2
itgadd.2
⊢
φ
→
x
∈
A
⟼
B
∈
𝐿
1
3
itgadd.3
⊢
φ
∧
x
∈
A
→
C
∈
V
4
itgadd.4
⊢
φ
→
x
∈
A
⟼
C
∈
𝐿
1
5
eqid
⊢
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℜ
B
ℜ
B
0
=
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℜ
B
ℜ
B
0
6
eqid
⊢
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℜ
B
−
ℜ
B
0
=
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℜ
B
−
ℜ
B
0
7
eqid
⊢
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℑ
B
ℑ
B
0
=
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℑ
B
ℑ
B
0
8
eqid
⊢
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℑ
B
−
ℑ
B
0
=
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℑ
B
−
ℑ
B
0
9
5
6
7
8
1
iblcnlem
⊢
φ
→
x
∈
A
⟼
B
∈
𝐿
1
↔
x
∈
A
⟼
B
∈
MblFn
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℜ
B
ℜ
B
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℜ
B
−
ℜ
B
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℑ
B
ℑ
B
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℑ
B
−
ℑ
B
0
∈
ℝ
10
2
9
mpbid
⊢
φ
→
x
∈
A
⟼
B
∈
MblFn
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℜ
B
ℜ
B
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℜ
B
−
ℜ
B
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℑ
B
ℑ
B
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℑ
B
−
ℑ
B
0
∈
ℝ
11
10
simp1d
⊢
φ
→
x
∈
A
⟼
B
∈
MblFn
12
11
1
mbfdm2
⊢
φ
→
A
∈
dom
vol
13
eqidd
⊢
φ
→
x
∈
A
⟼
B
=
x
∈
A
⟼
B
14
eqidd
⊢
φ
→
x
∈
A
⟼
C
=
x
∈
A
⟼
C
15
12
1
3
13
14
offval2
⊢
φ
→
x
∈
A
⟼
B
+
f
x
∈
A
⟼
C
=
x
∈
A
⟼
B
+
C
16
eqid
⊢
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℜ
C
ℜ
C
0
=
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℜ
C
ℜ
C
0
17
eqid
⊢
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℜ
C
−
ℜ
C
0
=
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℜ
C
−
ℜ
C
0
18
eqid
⊢
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℑ
C
ℑ
C
0
=
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℑ
C
ℑ
C
0
19
eqid
⊢
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℑ
C
−
ℑ
C
0
=
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℑ
C
−
ℑ
C
0
20
16
17
18
19
3
iblcnlem
⊢
φ
→
x
∈
A
⟼
C
∈
𝐿
1
↔
x
∈
A
⟼
C
∈
MblFn
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℜ
C
ℜ
C
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℜ
C
−
ℜ
C
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℑ
C
ℑ
C
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℑ
C
−
ℑ
C
0
∈
ℝ
21
4
20
mpbid
⊢
φ
→
x
∈
A
⟼
C
∈
MblFn
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℜ
C
ℜ
C
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℜ
C
−
ℜ
C
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℑ
C
ℑ
C
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℑ
C
−
ℑ
C
0
∈
ℝ
22
21
simp1d
⊢
φ
→
x
∈
A
⟼
C
∈
MblFn
23
11
22
mbfadd
⊢
φ
→
x
∈
A
⟼
B
+
f
x
∈
A
⟼
C
∈
MblFn
24
15
23
eqeltrrd
⊢
φ
→
x
∈
A
⟼
B
+
C
∈
MblFn
25
11
1
mbfmptcl
⊢
φ
∧
x
∈
A
→
B
∈
ℂ
26
25
recld
⊢
φ
∧
x
∈
A
→
ℜ
B
∈
ℝ
27
22
3
mbfmptcl
⊢
φ
∧
x
∈
A
→
C
∈
ℂ
28
27
recld
⊢
φ
∧
x
∈
A
→
ℜ
C
∈
ℝ
29
25
27
readdd
⊢
φ
∧
x
∈
A
→
ℜ
B
+
C
=
ℜ
B
+
ℜ
C
30
25
ismbfcn2
⊢
φ
→
x
∈
A
⟼
B
∈
MblFn
↔
x
∈
A
⟼
ℜ
B
∈
MblFn
∧
x
∈
A
⟼
ℑ
B
∈
MblFn
31
11
30
mpbid
⊢
φ
→
x
∈
A
⟼
ℜ
B
∈
MblFn
∧
x
∈
A
⟼
ℑ
B
∈
MblFn
32
31
simpld
⊢
φ
→
x
∈
A
⟼
ℜ
B
∈
MblFn
33
27
ismbfcn2
⊢
φ
→
x
∈
A
⟼
C
∈
MblFn
↔
x
∈
A
⟼
ℜ
C
∈
MblFn
∧
x
∈
A
⟼
ℑ
C
∈
MblFn
34
22
33
mpbid
⊢
φ
→
x
∈
A
⟼
ℜ
C
∈
MblFn
∧
x
∈
A
⟼
ℑ
C
∈
MblFn
35
34
simpld
⊢
φ
→
x
∈
A
⟼
ℜ
C
∈
MblFn
36
10
simp2d
⊢
φ
→
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℜ
B
ℜ
B
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℜ
B
−
ℜ
B
0
∈
ℝ
37
36
simpld
⊢
φ
→
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℜ
B
ℜ
B
0
∈
ℝ
38
21
simp2d
⊢
φ
→
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℜ
C
ℜ
C
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℜ
C
−
ℜ
C
0
∈
ℝ
39
38
simpld
⊢
φ
→
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℜ
C
ℜ
C
0
∈
ℝ
40
26
28
29
32
35
37
39
ibladdlem
⊢
φ
→
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℜ
B
+
C
ℜ
B
+
C
0
∈
ℝ
41
26
renegcld
⊢
φ
∧
x
∈
A
→
−
ℜ
B
∈
ℝ
42
28
renegcld
⊢
φ
∧
x
∈
A
→
−
ℜ
C
∈
ℝ
43
29
negeqd
⊢
φ
∧
x
∈
A
→
−
ℜ
B
+
C
=
−
ℜ
B
+
ℜ
C
44
26
recnd
⊢
φ
∧
x
∈
A
→
ℜ
B
∈
ℂ
45
28
recnd
⊢
φ
∧
x
∈
A
→
ℜ
C
∈
ℂ
46
44
45
negdid
⊢
φ
∧
x
∈
A
→
−
ℜ
B
+
ℜ
C
=
-
ℜ
B
+
−
ℜ
C
47
43
46
eqtrd
⊢
φ
∧
x
∈
A
→
−
ℜ
B
+
C
=
-
ℜ
B
+
−
ℜ
C
48
26
32
mbfneg
⊢
φ
→
x
∈
A
⟼
−
ℜ
B
∈
MblFn
49
28
35
mbfneg
⊢
φ
→
x
∈
A
⟼
−
ℜ
C
∈
MblFn
50
36
simprd
⊢
φ
→
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℜ
B
−
ℜ
B
0
∈
ℝ
51
38
simprd
⊢
φ
→
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℜ
C
−
ℜ
C
0
∈
ℝ
52
41
42
47
48
49
50
51
ibladdlem
⊢
φ
→
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℜ
B
+
C
−
ℜ
B
+
C
0
∈
ℝ
53
40
52
jca
⊢
φ
→
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℜ
B
+
C
ℜ
B
+
C
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℜ
B
+
C
−
ℜ
B
+
C
0
∈
ℝ
54
25
imcld
⊢
φ
∧
x
∈
A
→
ℑ
B
∈
ℝ
55
27
imcld
⊢
φ
∧
x
∈
A
→
ℑ
C
∈
ℝ
56
25
27
imaddd
⊢
φ
∧
x
∈
A
→
ℑ
B
+
C
=
ℑ
B
+
ℑ
C
57
31
simprd
⊢
φ
→
x
∈
A
⟼
ℑ
B
∈
MblFn
58
34
simprd
⊢
φ
→
x
∈
A
⟼
ℑ
C
∈
MblFn
59
10
simp3d
⊢
φ
→
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℑ
B
ℑ
B
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℑ
B
−
ℑ
B
0
∈
ℝ
60
59
simpld
⊢
φ
→
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℑ
B
ℑ
B
0
∈
ℝ
61
21
simp3d
⊢
φ
→
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℑ
C
ℑ
C
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℑ
C
−
ℑ
C
0
∈
ℝ
62
61
simpld
⊢
φ
→
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℑ
C
ℑ
C
0
∈
ℝ
63
54
55
56
57
58
60
62
ibladdlem
⊢
φ
→
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℑ
B
+
C
ℑ
B
+
C
0
∈
ℝ
64
54
renegcld
⊢
φ
∧
x
∈
A
→
−
ℑ
B
∈
ℝ
65
55
renegcld
⊢
φ
∧
x
∈
A
→
−
ℑ
C
∈
ℝ
66
56
negeqd
⊢
φ
∧
x
∈
A
→
−
ℑ
B
+
C
=
−
ℑ
B
+
ℑ
C
67
54
recnd
⊢
φ
∧
x
∈
A
→
ℑ
B
∈
ℂ
68
55
recnd
⊢
φ
∧
x
∈
A
→
ℑ
C
∈
ℂ
69
67
68
negdid
⊢
φ
∧
x
∈
A
→
−
ℑ
B
+
ℑ
C
=
-
ℑ
B
+
−
ℑ
C
70
66
69
eqtrd
⊢
φ
∧
x
∈
A
→
−
ℑ
B
+
C
=
-
ℑ
B
+
−
ℑ
C
71
54
57
mbfneg
⊢
φ
→
x
∈
A
⟼
−
ℑ
B
∈
MblFn
72
55
58
mbfneg
⊢
φ
→
x
∈
A
⟼
−
ℑ
C
∈
MblFn
73
59
simprd
⊢
φ
→
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℑ
B
−
ℑ
B
0
∈
ℝ
74
61
simprd
⊢
φ
→
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℑ
C
−
ℑ
C
0
∈
ℝ
75
64
65
70
71
72
73
74
ibladdlem
⊢
φ
→
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℑ
B
+
C
−
ℑ
B
+
C
0
∈
ℝ
76
63
75
jca
⊢
φ
→
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℑ
B
+
C
ℑ
B
+
C
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℑ
B
+
C
−
ℑ
B
+
C
0
∈
ℝ
77
eqid
⊢
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℜ
B
+
C
ℜ
B
+
C
0
=
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℜ
B
+
C
ℜ
B
+
C
0
78
eqid
⊢
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℜ
B
+
C
−
ℜ
B
+
C
0
=
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℜ
B
+
C
−
ℜ
B
+
C
0
79
eqid
⊢
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℑ
B
+
C
ℑ
B
+
C
0
=
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℑ
B
+
C
ℑ
B
+
C
0
80
eqid
⊢
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℑ
B
+
C
−
ℑ
B
+
C
0
=
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℑ
B
+
C
−
ℑ
B
+
C
0
81
ovexd
⊢
φ
∧
x
∈
A
→
B
+
C
∈
V
82
77
78
79
80
81
iblcnlem
⊢
φ
→
x
∈
A
⟼
B
+
C
∈
𝐿
1
↔
x
∈
A
⟼
B
+
C
∈
MblFn
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℜ
B
+
C
ℜ
B
+
C
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℜ
B
+
C
−
ℜ
B
+
C
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
ℑ
B
+
C
ℑ
B
+
C
0
∈
ℝ
∧
∫
2
x
∈
ℝ
⟼
if
x
∈
A
∧
0
≤
−
ℑ
B
+
C
−
ℑ
B
+
C
0
∈
ℝ
83
24
53
76
82
mpbir3and
⊢
φ
→
x
∈
A
⟼
B
+
C
∈
𝐿
1