Witt space
= Witt space
{c}
A rational <Witt space> is a <stratified pseudomanifold> such that the link $L$ of every stratum of odd codimension $2r+1$ satisfies $IH_r^{\bar m}(L;\mathbb Q)=0$. This removes the only difference between lower and upper middle extensions and gives rational middle-perversity <Poincare duality> on closed oriented <Witt spaces>.