2025-11-09

1415: Almost-Everywhere over Measure Space

<The previous article in this series | The table of contents of this series | The next article in this series>

definition of almost-everywhere over measure space

Topics


About: measure space

The table of contents of this article


Starting Context



Target Context


  • The reader will have a definition of almost-everywhere over measure space.

Orientation


There is a list of definitions discussed so far in this site.

There is a list of propositions discussed so far in this site.


Main Body


1: Structured Description


Here is the rules of Structured Description.

Entities:
\( (M, A, \mu)\): \(\in \{\text{ the measure spaces }\}\)
\(*S\): \(\subseteq M\)
//

Conditions:
\(M \setminus S \in \{\text{ the negligible subsets of } M\}\)
//

A prevalent notation for being almost-everywhere is \(a.e\), or \(\mu-a.e\) if \(\mu\) is needed to be specified.


2: Note


These are some typical usages.

For some maps, \(f_1, f_2: M \to F\), \(f =_{a.e} g\), which means that \(\{m \in M \vert f (m) \neq g (m)\}\) is a negligible subset of \(M\).

Likewise, \(f \lt_{a.e} g\) or \(f \le_{a.e} g\).


References


<The previous article in this series | The table of contents of this series | The next article in this series>