Change name for →Qπ - please suggest!

[Fortin]

Prime currently uses approx to return a floating point approximation in CAS, so that could get wrongway confusing.

FP for floating point seems to cover the inputs - both real or complex. And qpi returns more than just rational numbers so 'rat' may be too specific and limiting.

Maybe something like:
fp2exact or fp2e

... although, it's really an "approximately exact" value...