Generated σ-algebra

Dependencies:

  1. σ-algebra

Let $\Fcal$ be a subset of the power-set of $X$.

Define $\sigma(\Fcal)$ as the set containing all the subsets of $X$ that can be made from elements of $\Fcal$ by a countable number of complement, union and intersection operations. Then $\sigma(\Fcal)$ is a $\sigma$-algebra.

The proof follows almost by definition.

$\sigma(\Fcal)$ is called the '$\sigma$-algebra generated by $\Fcal$'.

Dependency for:

  1. Random variable
  2. Independence of random variables (incomplete)
  3. Borel algebra

Info:

Transitive dependencies:

  1. /sets-and-relations/countable-set
  2. σ-algebra