Mathematical Equality

[stefnotch]

Checking whether two equations or formulas are equal is surprisingly tricky.

For example, there are cases when the equality doesn't hold up for all real numbers, just some.
Like taking 0/x = 1
and multiplying it by x, to get 0 = x
Those two equations are not strictly equal. The first one is not defined for x = 0. The second one very much is.

And once one goes deeper down the rabbit hole, things like this monstrosity come up.
1/2*arcsin(x) + arctan(sqrt(1-x)/sqrt(1+x)) is equal to pi/4, for |x| < 1

I personally opted for the tried and tested strategy of "leaving the problem to someone else". In my case, we ended up using Sympy with Pyodide. Another solid option is using Xcas, which does have a Javascript build. I think swiftcalcs uses that.

And finally, if you think there would be any nice places where we could collaborate or share some of the workload, I'd love to hear about them!