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 e. _V , m e. U. 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
 |-  U. 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 e. _V , m e. U. ran measures |-> ( ( ( metUnif ` ( w sitm m ) ) CnExt ( UnifSt ` w ) ) ` ( w sitg m ) ) )
21 0 20 wceq
 |-  itgm = ( w e. _V , m e. U. ran measures |-> ( ( ( metUnif ` ( w sitm m ) ) CnExt ( UnifSt ` w ) ) ` ( w sitg m ) ) )