This is the current revision of this page, as edited by Erel Segal(talk | contribs) at 14:33, 9 January 2023(This page should be a stand-alone article and not a redirect. But since I do not have time to find references, I make it a redirect to a subsection that gives the basic definition.). The present address (URL) is a permanent link to this version.Revision as of 14:33, 9 January 2023 by Erel Segal(talk | contribs)(This page should be a stand-alone article and not a redirect. But since I do not have time to find references, I make it a redirect to a subsection that gives the basic definition.)
