(* 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 Reference Manual - 15 Dec 2011