Invariant sigma-algebra
= Invariant sigma-algebra
{title2=$\mathcal I$}
The invariant sigma-algebra of $T$ consists, modulo null sets, of measurable sets $A$ satisfying $T^{-1}A=A$.
= Invariant sigma-algebra
{title2=$\mathcal I$}
The invariant sigma-algebra of $T$ consists, modulo null sets, of measurable sets $A$ satisfying $T^{-1}A=A$.