Invariant under closed maps with respect to separation axioms

We discuss whether several separation axioms are preserved under closed maps. Consider the following diagram. Diagram 1 – Separation Axioms …. ….……….Perfectly normal …………………… ….……….Hereditarily normal …………………… ….……….Normal …………………… ….……..Completely regular …………………… ….……….Regular …………………… ….……….Hausdorff …………………… ….……….Every one-point set is … Continue reading →