[otabdeveloper4]

"Mathematicians" don't need NaN's and Inf's.

These things come straight from overflow and underflow behaviour of floating point bit representations. I'd guess some sort of IEEE flag exists to emit an interrupt if over/underflow happens, but nobody really wants those.

[SideQuark]

They don’t come solely from over/underflow. The do come from math. Sort of neg, 1/0, and plenty of other mathematical operations result in these, no matter how you want to store numbers.