Anonanon 152k1212 gold badges233233 silver badges398398 bronze badges $endgroup$ four $begingroup$ That's excellent thanks a bunch! I also posted the same concern in this article: math.stackexchange.com/questions/2135276/… that you might have some insight on? $endgroup$ The Levi-Civita image is most often used in three and 4 Proportions, also to some extent https://carlu233fby1.azzablog.com/profile