1 665c255d 2023-08-04 jrmu (defun div-interval (x y)
2 665c255d 2023-08-04 jrmu   (if (and
3 665c255d 2023-08-04 jrmu        (>= (upper-bound y) 0)
4 665c255d 2023-08-04 jrmu        (<= (lower-bound y) 0))
5 665c255d 2023-08-04 jrmu       (error "Denominator spans zero")
6 665c255d 2023-08-04 jrmu       (mul-interval
7 665c255d 2023-08-04 jrmu        x
8 665c255d 2023-08-04 jrmu        (make-interval (/ 1.0 (upper-bound y))
9 665c255d 2023-08-04 jrmu 		      (/ 1.0 (lower-bound y))))))