Probability space
Set
context
$X $ … set
definiendum
$ \langle X,\Sigma,P\rangle\in \mathrm{ProbabilitySpace}(X) $
inclusion
$ \langle X,\Sigma,P\rangle $ … measure space
postulate
$ P(X)=1 $
Reference
Wikipedia:
Probability space
Subset of
Measure space