{"articles":{"sigma-algebra-definition@measure-theory":{"content":"<p>A σ-algebra \\(\\Sigma\\) on \\(A\\) is a subset of \\({\\cal{P} (A)}\\) where: <ul></ul> <br> A set in a σ-algebra is called a measurable set. <br> The \"σ-\" prefix is used to name things having countable properties. In this case, countable union.</p>","names":[[["Definition",""]]]}},"style":"Definition"}