A transformation T of a structure D is structure-preserving if T(D) has the same symmetry group as the original one: Aut(T(D)) ~= Aut(D).https://twitter.com/literalbanana/status/982816860566532096 …
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
Yeah, what I'm arguing I think is that group actions are one language to (very rigorously) describe some of these notions, not all of them. Certainly when you look at something like https://en.wikipedia.org/wiki/Islamic_geometric_patterns … it's almost necessary.
But it tells you nothing about why he prefers the third rectangle, except by omission.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.