Metamath Proof Explorer


Theorem ibladdnc

Description: Choice-free analogue of itgadd . A measurability hypothesis is necessitated by the loss of mbfadd ; for large classes of functions, such as continuous functions, it should be relatively easy to show. (Contributed by Brendan Leahy, 1-Nov-2017)

Ref Expression
Hypotheses ibladdnc.1 ( ( 𝜑𝑥𝐴 ) → 𝐵𝑉 )
ibladdnc.2 ( 𝜑 → ( 𝑥𝐴𝐵 ) ∈ 𝐿1 )
ibladdnc.3 ( ( 𝜑𝑥𝐴 ) → 𝐶𝑉 )
ibladdnc.4 ( 𝜑 → ( 𝑥𝐴𝐶 ) ∈ 𝐿1 )
ibladdnc.m ( 𝜑 → ( 𝑥𝐴 ↦ ( 𝐵 + 𝐶 ) ) ∈ MblFn )
Assertion ibladdnc ( 𝜑 → ( 𝑥𝐴 ↦ ( 𝐵 + 𝐶 ) ) ∈ 𝐿1 )

Proof

Step Hyp Ref Expression
1 ibladdnc.1 ( ( 𝜑𝑥𝐴 ) → 𝐵𝑉 )
2 ibladdnc.2 ( 𝜑 → ( 𝑥𝐴𝐵 ) ∈ 𝐿1 )
3 ibladdnc.3 ( ( 𝜑𝑥𝐴 ) → 𝐶𝑉 )
4 ibladdnc.4 ( 𝜑 → ( 𝑥𝐴𝐶 ) ∈ 𝐿1 )
5 ibladdnc.m ( 𝜑 → ( 𝑥𝐴 ↦ ( 𝐵 + 𝐶 ) ) ∈ MblFn )
6 iblmbf ( ( 𝑥𝐴𝐵 ) ∈ 𝐿1 → ( 𝑥𝐴𝐵 ) ∈ MblFn )
7 2 6 syl ( 𝜑 → ( 𝑥𝐴𝐵 ) ∈ MblFn )
8 7 1 mbfmptcl ( ( 𝜑𝑥𝐴 ) → 𝐵 ∈ ℂ )
9 8 recld ( ( 𝜑𝑥𝐴 ) → ( ℜ ‘ 𝐵 ) ∈ ℝ )
10 iblmbf ( ( 𝑥𝐴𝐶 ) ∈ 𝐿1 → ( 𝑥𝐴𝐶 ) ∈ MblFn )
11 4 10 syl ( 𝜑 → ( 𝑥𝐴𝐶 ) ∈ MblFn )
12 11 3 mbfmptcl ( ( 𝜑𝑥𝐴 ) → 𝐶 ∈ ℂ )
13 12 recld ( ( 𝜑𝑥𝐴 ) → ( ℜ ‘ 𝐶 ) ∈ ℝ )
14 8 12 readdd ( ( 𝜑𝑥𝐴 ) → ( ℜ ‘ ( 𝐵 + 𝐶 ) ) = ( ( ℜ ‘ 𝐵 ) + ( ℜ ‘ 𝐶 ) ) )
15 8 ismbfcn2 ( 𝜑 → ( ( 𝑥𝐴𝐵 ) ∈ MblFn ↔ ( ( 𝑥𝐴 ↦ ( ℜ ‘ 𝐵 ) ) ∈ MblFn ∧ ( 𝑥𝐴 ↦ ( ℑ ‘ 𝐵 ) ) ∈ MblFn ) ) )
16 7 15 mpbid ( 𝜑 → ( ( 𝑥𝐴 ↦ ( ℜ ‘ 𝐵 ) ) ∈ MblFn ∧ ( 𝑥𝐴 ↦ ( ℑ ‘ 𝐵 ) ) ∈ MblFn ) )
17 16 simpld ( 𝜑 → ( 𝑥𝐴 ↦ ( ℜ ‘ 𝐵 ) ) ∈ MblFn )
18 eqid ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℜ ‘ 𝐵 ) ) , ( ℜ ‘ 𝐵 ) , 0 ) ) ) = ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℜ ‘ 𝐵 ) ) , ( ℜ ‘ 𝐵 ) , 0 ) ) )
19 eqid ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℜ ‘ 𝐵 ) ) , - ( ℜ ‘ 𝐵 ) , 0 ) ) ) = ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℜ ‘ 𝐵 ) ) , - ( ℜ ‘ 𝐵 ) , 0 ) ) )
20 eqid ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℑ ‘ 𝐵 ) ) , ( ℑ ‘ 𝐵 ) , 0 ) ) ) = ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℑ ‘ 𝐵 ) ) , ( ℑ ‘ 𝐵 ) , 0 ) ) )
21 eqid ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℑ ‘ 𝐵 ) ) , - ( ℑ ‘ 𝐵 ) , 0 ) ) ) = ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℑ ‘ 𝐵 ) ) , - ( ℑ ‘ 𝐵 ) , 0 ) ) )
22 18 19 20 21 1 iblcnlem ( 𝜑 → ( ( 𝑥𝐴𝐵 ) ∈ 𝐿1 ↔ ( ( 𝑥𝐴𝐵 ) ∈ MblFn ∧ ( ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℜ ‘ 𝐵 ) ) , ( ℜ ‘ 𝐵 ) , 0 ) ) ) ∈ ℝ ∧ ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℜ ‘ 𝐵 ) ) , - ( ℜ ‘ 𝐵 ) , 0 ) ) ) ∈ ℝ ) ∧ ( ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℑ ‘ 𝐵 ) ) , ( ℑ ‘ 𝐵 ) , 0 ) ) ) ∈ ℝ ∧ ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℑ ‘ 𝐵 ) ) , - ( ℑ ‘ 𝐵 ) , 0 ) ) ) ∈ ℝ ) ) ) )
23 2 22 mpbid ( 𝜑 → ( ( 𝑥𝐴𝐵 ) ∈ MblFn ∧ ( ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℜ ‘ 𝐵 ) ) , ( ℜ ‘ 𝐵 ) , 0 ) ) ) ∈ ℝ ∧ ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℜ ‘ 𝐵 ) ) , - ( ℜ ‘ 𝐵 ) , 0 ) ) ) ∈ ℝ ) ∧ ( ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℑ ‘ 𝐵 ) ) , ( ℑ ‘ 𝐵 ) , 0 ) ) ) ∈ ℝ ∧ ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℑ ‘ 𝐵 ) ) , - ( ℑ ‘ 𝐵 ) , 0 ) ) ) ∈ ℝ ) ) )
24 23 simp2d ( 𝜑 → ( ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℜ ‘ 𝐵 ) ) , ( ℜ ‘ 𝐵 ) , 0 ) ) ) ∈ ℝ ∧ ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℜ ‘ 𝐵 ) ) , - ( ℜ ‘ 𝐵 ) , 0 ) ) ) ∈ ℝ ) )
25 24 simpld ( 𝜑 → ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℜ ‘ 𝐵 ) ) , ( ℜ ‘ 𝐵 ) , 0 ) ) ) ∈ ℝ )
26 eqid ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℜ ‘ 𝐶 ) ) , ( ℜ ‘ 𝐶 ) , 0 ) ) ) = ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℜ ‘ 𝐶 ) ) , ( ℜ ‘ 𝐶 ) , 0 ) ) )
27 eqid ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℜ ‘ 𝐶 ) ) , - ( ℜ ‘ 𝐶 ) , 0 ) ) ) = ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℜ ‘ 𝐶 ) ) , - ( ℜ ‘ 𝐶 ) , 0 ) ) )
28 eqid ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℑ ‘ 𝐶 ) ) , ( ℑ ‘ 𝐶 ) , 0 ) ) ) = ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℑ ‘ 𝐶 ) ) , ( ℑ ‘ 𝐶 ) , 0 ) ) )
29 eqid ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℑ ‘ 𝐶 ) ) , - ( ℑ ‘ 𝐶 ) , 0 ) ) ) = ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℑ ‘ 𝐶 ) ) , - ( ℑ ‘ 𝐶 ) , 0 ) ) )
30 26 27 28 29 3 iblcnlem ( 𝜑 → ( ( 𝑥𝐴𝐶 ) ∈ 𝐿1 ↔ ( ( 𝑥𝐴𝐶 ) ∈ MblFn ∧ ( ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℜ ‘ 𝐶 ) ) , ( ℜ ‘ 𝐶 ) , 0 ) ) ) ∈ ℝ ∧ ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℜ ‘ 𝐶 ) ) , - ( ℜ ‘ 𝐶 ) , 0 ) ) ) ∈ ℝ ) ∧ ( ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℑ ‘ 𝐶 ) ) , ( ℑ ‘ 𝐶 ) , 0 ) ) ) ∈ ℝ ∧ ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℑ ‘ 𝐶 ) ) , - ( ℑ ‘ 𝐶 ) , 0 ) ) ) ∈ ℝ ) ) ) )
31 4 30 mpbid ( 𝜑 → ( ( 𝑥𝐴𝐶 ) ∈ MblFn ∧ ( ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℜ ‘ 𝐶 ) ) , ( ℜ ‘ 𝐶 ) , 0 ) ) ) ∈ ℝ ∧ ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℜ ‘ 𝐶 ) ) , - ( ℜ ‘ 𝐶 ) , 0 ) ) ) ∈ ℝ ) ∧ ( ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℑ ‘ 𝐶 ) ) , ( ℑ ‘ 𝐶 ) , 0 ) ) ) ∈ ℝ ∧ ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℑ ‘ 𝐶 ) ) , - ( ℑ ‘ 𝐶 ) , 0 ) ) ) ∈ ℝ ) ) )
32 31 simp2d ( 𝜑 → ( ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℜ ‘ 𝐶 ) ) , ( ℜ ‘ 𝐶 ) , 0 ) ) ) ∈ ℝ ∧ ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℜ ‘ 𝐶 ) ) , - ( ℜ ‘ 𝐶 ) , 0 ) ) ) ∈ ℝ ) )
33 32 simpld ( 𝜑 → ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℜ ‘ 𝐶 ) ) , ( ℜ ‘ 𝐶 ) , 0 ) ) ) ∈ ℝ )
34 9 13 14 17 25 33 ibladdnclem ( 𝜑 → ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℜ ‘ ( 𝐵 + 𝐶 ) ) ) , ( ℜ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) ) ∈ ℝ )
35 9 renegcld ( ( 𝜑𝑥𝐴 ) → - ( ℜ ‘ 𝐵 ) ∈ ℝ )
36 13 renegcld ( ( 𝜑𝑥𝐴 ) → - ( ℜ ‘ 𝐶 ) ∈ ℝ )
37 14 negeqd ( ( 𝜑𝑥𝐴 ) → - ( ℜ ‘ ( 𝐵 + 𝐶 ) ) = - ( ( ℜ ‘ 𝐵 ) + ( ℜ ‘ 𝐶 ) ) )
38 9 recnd ( ( 𝜑𝑥𝐴 ) → ( ℜ ‘ 𝐵 ) ∈ ℂ )
39 13 recnd ( ( 𝜑𝑥𝐴 ) → ( ℜ ‘ 𝐶 ) ∈ ℂ )
40 38 39 negdid ( ( 𝜑𝑥𝐴 ) → - ( ( ℜ ‘ 𝐵 ) + ( ℜ ‘ 𝐶 ) ) = ( - ( ℜ ‘ 𝐵 ) + - ( ℜ ‘ 𝐶 ) ) )
41 37 40 eqtrd ( ( 𝜑𝑥𝐴 ) → - ( ℜ ‘ ( 𝐵 + 𝐶 ) ) = ( - ( ℜ ‘ 𝐵 ) + - ( ℜ ‘ 𝐶 ) ) )
42 9 17 mbfneg ( 𝜑 → ( 𝑥𝐴 ↦ - ( ℜ ‘ 𝐵 ) ) ∈ MblFn )
43 24 simprd ( 𝜑 → ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℜ ‘ 𝐵 ) ) , - ( ℜ ‘ 𝐵 ) , 0 ) ) ) ∈ ℝ )
44 32 simprd ( 𝜑 → ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℜ ‘ 𝐶 ) ) , - ( ℜ ‘ 𝐶 ) , 0 ) ) ) ∈ ℝ )
45 35 36 41 42 43 44 ibladdnclem ( 𝜑 → ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℜ ‘ ( 𝐵 + 𝐶 ) ) ) , - ( ℜ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) ) ∈ ℝ )
46 34 45 jca ( 𝜑 → ( ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℜ ‘ ( 𝐵 + 𝐶 ) ) ) , ( ℜ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) ) ∈ ℝ ∧ ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℜ ‘ ( 𝐵 + 𝐶 ) ) ) , - ( ℜ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) ) ∈ ℝ ) )
47 8 imcld ( ( 𝜑𝑥𝐴 ) → ( ℑ ‘ 𝐵 ) ∈ ℝ )
48 12 imcld ( ( 𝜑𝑥𝐴 ) → ( ℑ ‘ 𝐶 ) ∈ ℝ )
49 8 12 imaddd ( ( 𝜑𝑥𝐴 ) → ( ℑ ‘ ( 𝐵 + 𝐶 ) ) = ( ( ℑ ‘ 𝐵 ) + ( ℑ ‘ 𝐶 ) ) )
50 16 simprd ( 𝜑 → ( 𝑥𝐴 ↦ ( ℑ ‘ 𝐵 ) ) ∈ MblFn )
51 23 simp3d ( 𝜑 → ( ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℑ ‘ 𝐵 ) ) , ( ℑ ‘ 𝐵 ) , 0 ) ) ) ∈ ℝ ∧ ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℑ ‘ 𝐵 ) ) , - ( ℑ ‘ 𝐵 ) , 0 ) ) ) ∈ ℝ ) )
52 51 simpld ( 𝜑 → ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℑ ‘ 𝐵 ) ) , ( ℑ ‘ 𝐵 ) , 0 ) ) ) ∈ ℝ )
53 31 simp3d ( 𝜑 → ( ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℑ ‘ 𝐶 ) ) , ( ℑ ‘ 𝐶 ) , 0 ) ) ) ∈ ℝ ∧ ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℑ ‘ 𝐶 ) ) , - ( ℑ ‘ 𝐶 ) , 0 ) ) ) ∈ ℝ ) )
54 53 simpld ( 𝜑 → ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℑ ‘ 𝐶 ) ) , ( ℑ ‘ 𝐶 ) , 0 ) ) ) ∈ ℝ )
55 47 48 49 50 52 54 ibladdnclem ( 𝜑 → ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℑ ‘ ( 𝐵 + 𝐶 ) ) ) , ( ℑ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) ) ∈ ℝ )
56 47 renegcld ( ( 𝜑𝑥𝐴 ) → - ( ℑ ‘ 𝐵 ) ∈ ℝ )
57 48 renegcld ( ( 𝜑𝑥𝐴 ) → - ( ℑ ‘ 𝐶 ) ∈ ℝ )
58 49 negeqd ( ( 𝜑𝑥𝐴 ) → - ( ℑ ‘ ( 𝐵 + 𝐶 ) ) = - ( ( ℑ ‘ 𝐵 ) + ( ℑ ‘ 𝐶 ) ) )
59 47 recnd ( ( 𝜑𝑥𝐴 ) → ( ℑ ‘ 𝐵 ) ∈ ℂ )
60 48 recnd ( ( 𝜑𝑥𝐴 ) → ( ℑ ‘ 𝐶 ) ∈ ℂ )
61 59 60 negdid ( ( 𝜑𝑥𝐴 ) → - ( ( ℑ ‘ 𝐵 ) + ( ℑ ‘ 𝐶 ) ) = ( - ( ℑ ‘ 𝐵 ) + - ( ℑ ‘ 𝐶 ) ) )
62 58 61 eqtrd ( ( 𝜑𝑥𝐴 ) → - ( ℑ ‘ ( 𝐵 + 𝐶 ) ) = ( - ( ℑ ‘ 𝐵 ) + - ( ℑ ‘ 𝐶 ) ) )
63 47 50 mbfneg ( 𝜑 → ( 𝑥𝐴 ↦ - ( ℑ ‘ 𝐵 ) ) ∈ MblFn )
64 51 simprd ( 𝜑 → ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℑ ‘ 𝐵 ) ) , - ( ℑ ‘ 𝐵 ) , 0 ) ) ) ∈ ℝ )
65 53 simprd ( 𝜑 → ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℑ ‘ 𝐶 ) ) , - ( ℑ ‘ 𝐶 ) , 0 ) ) ) ∈ ℝ )
66 56 57 62 63 64 65 ibladdnclem ( 𝜑 → ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℑ ‘ ( 𝐵 + 𝐶 ) ) ) , - ( ℑ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) ) ∈ ℝ )
67 55 66 jca ( 𝜑 → ( ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℑ ‘ ( 𝐵 + 𝐶 ) ) ) , ( ℑ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) ) ∈ ℝ ∧ ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℑ ‘ ( 𝐵 + 𝐶 ) ) ) , - ( ℑ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) ) ∈ ℝ ) )
68 eqid ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℜ ‘ ( 𝐵 + 𝐶 ) ) ) , ( ℜ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) ) = ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℜ ‘ ( 𝐵 + 𝐶 ) ) ) , ( ℜ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) )
69 eqid ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℜ ‘ ( 𝐵 + 𝐶 ) ) ) , - ( ℜ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) ) = ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℜ ‘ ( 𝐵 + 𝐶 ) ) ) , - ( ℜ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) )
70 eqid ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℑ ‘ ( 𝐵 + 𝐶 ) ) ) , ( ℑ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) ) = ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℑ ‘ ( 𝐵 + 𝐶 ) ) ) , ( ℑ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) )
71 eqid ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℑ ‘ ( 𝐵 + 𝐶 ) ) ) , - ( ℑ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) ) = ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℑ ‘ ( 𝐵 + 𝐶 ) ) ) , - ( ℑ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) )
72 ovexd ( ( 𝜑𝑥𝐴 ) → ( 𝐵 + 𝐶 ) ∈ V )
73 68 69 70 71 72 iblcnlem ( 𝜑 → ( ( 𝑥𝐴 ↦ ( 𝐵 + 𝐶 ) ) ∈ 𝐿1 ↔ ( ( 𝑥𝐴 ↦ ( 𝐵 + 𝐶 ) ) ∈ MblFn ∧ ( ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℜ ‘ ( 𝐵 + 𝐶 ) ) ) , ( ℜ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) ) ∈ ℝ ∧ ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℜ ‘ ( 𝐵 + 𝐶 ) ) ) , - ( ℜ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) ) ∈ ℝ ) ∧ ( ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ ( ℑ ‘ ( 𝐵 + 𝐶 ) ) ) , ( ℑ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) ) ∈ ℝ ∧ ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ if ( ( 𝑥𝐴 ∧ 0 ≤ - ( ℑ ‘ ( 𝐵 + 𝐶 ) ) ) , - ( ℑ ‘ ( 𝐵 + 𝐶 ) ) , 0 ) ) ) ∈ ℝ ) ) ) )
74 5 46 67 73 mpbir3and ( 𝜑 → ( 𝑥𝐴 ↦ ( 𝐵 + 𝐶 ) ) ∈ 𝐿1 )