Metamath Proof Explorer


Definition df-itgm

Description: Define the Bochner integral as the extension by continuity of the Bochnel integral for simple functions.

Bogachev first defines 'fundamental in the mean' sequences, in definition 2.3.1 of Bogachev p. 116, and notes that those are actually Cauchy sequences for the pseudometric ( w sitm m ) .

He then defines the Bochner integral in chapter 2.4.4 in Bogachev p. 118. The definition of the Lebesgue integral, df-itg .

(Contributed by Thierry Arnoux, 13-Feb-2018)

Ref Expression
Assertion df-itgm itgm = ( 𝑤 ∈ V , 𝑚 ran measures ↦ ( ( ( metUnif ‘ ( 𝑤 sitm 𝑚 ) ) CnExt ( UnifSt ‘ 𝑤 ) ) ‘ ( 𝑤 sitg 𝑚 ) ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 citgm itgm
1 vw 𝑤
2 cvv V
3 vm 𝑚
4 cmeas measures
5 4 crn ran measures
6 5 cuni ran measures
7 cmetu metUnif
8 1 cv 𝑤
9 csitm sitm
10 3 cv 𝑚
11 8 10 9 co ( 𝑤 sitm 𝑚 )
12 11 7 cfv ( metUnif ‘ ( 𝑤 sitm 𝑚 ) )
13 ccnext CnExt
14 cuss UnifSt
15 8 14 cfv ( UnifSt ‘ 𝑤 )
16 12 15 13 co ( ( metUnif ‘ ( 𝑤 sitm 𝑚 ) ) CnExt ( UnifSt ‘ 𝑤 ) )
17 csitg sitg
18 8 10 17 co ( 𝑤 sitg 𝑚 )
19 18 16 cfv ( ( ( metUnif ‘ ( 𝑤 sitm 𝑚 ) ) CnExt ( UnifSt ‘ 𝑤 ) ) ‘ ( 𝑤 sitg 𝑚 ) )
20 1 3 2 6 19 cmpo ( 𝑤 ∈ V , 𝑚 ran measures ↦ ( ( ( metUnif ‘ ( 𝑤 sitm 𝑚 ) ) CnExt ( UnifSt ‘ 𝑤 ) ) ‘ ( 𝑤 sitg 𝑚 ) ) )
21 0 20 wceq itgm = ( 𝑤 ∈ V , 𝑚 ran measures ↦ ( ( ( metUnif ‘ ( 𝑤 sitm 𝑚 ) ) CnExt ( UnifSt ‘ 𝑤 ) ) ‘ ( 𝑤 sitg 𝑚 ) ) )