(* 2 pi) as a single-float.
(* 2 pi)
single-float
graphics-ports
The constant f2pi is the result of (float (* 2.0 cl:pi) 1.0). It is a cl:single-float.
f2pi
(float (* 2.0 cl:pi) 1.0)
cl:single-float
fpi fpi-by-2
CAPI User Guide and Reference Manual (Windows version) - 3 Aug 2017