English Borromean rings Cited by user David Eppstein on 15 Feb 2021 In mathematics, the Borromean rings are three simple closed curves in three-dimensional space that are topologically linked and cannot be separated from each other, but…
English Haken manifold Cited by user Turgidson on 21 Aug 2019 In mathematics, a Haken manifold is a compact, P²-irreducible 3-manifold that is sufficiently large, meaning that it contains a properly embedded two-sided…