Join of measurable partitions
= Join of measurable partitions
{title2=$\xi\vee\eta$}
The join is the common refinement of two <measurable partitions>, with atoms given by their nonempty intersections. For a <measure-preserving transformation>, the block partition is $\xi_0^{n-1}=\bigvee_{j=0}^{n-1}T^{-j}\xi$.