I know that Desmos supports ∞, -∞, and NaN as three different things – after all, {|x| = ∞: sign(x), {x = x: 0, 2}} will return 0 for normal numbers, 1 for ∞, -1 for -∞, and 2 for NaN (such as 0/0).
In that case, why does Desmos label them all as undefined if there’s more meaning than that?
Surely it’s not difficult to differentiate them (after all, I just did), so why do they slap the label of undefined on any non-normal number?