Description: Define 'almost everywhere' with regard to a measure M . A property holds almost everywhere if the measure of the set where it does not hold has measure zero. (Contributed by Thierry Arnoux, 20-Oct-2017)
Ref | Expression | ||
---|---|---|---|
Assertion | df-ae | |- ae = { <. a , m >. | ( m ` ( U. dom m \ a ) ) = 0 } |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | cae | |- ae |
|
1 | va | |- a |
|
2 | vm | |- m |
|
3 | 2 | cv | |- m |
4 | 3 | cdm | |- dom m |
5 | 4 | cuni | |- U. dom m |
6 | 1 | cv | |- a |
7 | 5 6 | cdif | |- ( U. dom m \ a ) |
8 | 7 3 | cfv | |- ( m ` ( U. dom m \ a ) ) |
9 | cc0 | |- 0 |
|
10 | 8 9 | wceq | |- ( m ` ( U. dom m \ a ) ) = 0 |
11 | 10 1 2 | copab | |- { <. a , m >. | ( m ` ( U. dom m \ a ) ) = 0 } |
12 | 0 11 | wceq | |- ae = { <. a , m >. | ( m ` ( U. dom m \ a ) ) = 0 } |