Entropy of a countable measurable partition
= Entropy of a countable measurable partition
{title2=$H_\mu(\xi)$}
For a countable <measurable partition>, its entropy is $H_\mu(\xi)=-\sum_{A\in\xi}\mu(A)\log\mu(A)$, with $0\log0=0$. This extends <entropy of a finite measurable partition> and is allowed to be infinite.