vit_tucek

Associativity says that the order of __evaluation__ of operations doesn't matter. You are talking about commutativity.

Is there a comparison of Sage capabilities with other CAS such as Mathematica, Matlab or Maple?

I've once redone a simple Metapost diagram in TikZ and was surprised how similar these languages are. At least for such a simple task that it was.

I think dashed lines for rays would reduce a lot of visual clutter.

Anyway, I long for the day when someone writes a similar toy for a non-Euclidean plane.

I use cloud.sagemath.com for offloading heavy computational work.