(defun map-range (a1 a2 b1 b2 s)
(+ b1
(/ (* (- s a1)
(- b2 b1))
(- a2 a1))))
(loop
for i from 0 to 10
do (format t "~F maps to ~F~C" i
(map-range 0 10 -1 0 i)
#\Newline))