[wcarey]

Right - that argument, I'm suggesting, is way beyond most fourth graders even in its modern algebraic form. It relies on lots of algebraic techniques that aren't generally taught until 7th or 8th grade.

It's not, like, rocket science, but it's not trivial either.

[yesenadam]

Well, it does seem to me fair to say that "it is trivial primary school arithmetic". But I guess the truth of whether it is or it isn't trivial, isn't really something that can be scientifically tested – it rests on how exactly you define "trivial", what you count as the involved operations etc. Well, we could go further into it if we wanted (e.g. What are these "lots of algebraic techniques" involved in these 2 little steps?!) but having asserted our rivals claims without much evidence feels like a good place to stop – this time. :-)

Edit: Or I suppose "tabooing"[0] the word trivial would have helped – it was the trouble-maker.

[0] https://www.lesswrong.com/posts/WBdvyyHLdxZSAMmoz/taboo-your...