measurable

Measurable space

context	$X$
definiendum	$\langle X,\Sigma\rangle\in \mathrm{MeasurableSpace}(X)$
postulate	$\Sigma \in \mathrm{SigmaAlgebra}(X)$

Every σ-algebra gives us a measurable space.

We call a set $X$ measurable if there is a sigma-algebra over it.