DescriptionCrossing numbers trefoil.png English: Trefoil knot without 3-fold symmetry with crossings labeled. Date 2 April 2013, 03:35:29 Source Own work...
This image is a derivative work of the following images: File:Knot-trefoil-numdir-128.png licensed with Cc-by-sa-3.0-migrated-with-disclaimers, GFDL-en,...