1 665c255d 2023-08-04 jrmu (defun unique-triples (n)
 2 665c255d 2023-08-04 jrmu   "Unique triples of numbers <= n"
 3 665c255d 2023-08-04 jrmu   (flatmap
 4 665c255d 2023-08-04 jrmu    (lambda (i)
 5 665c255d 2023-08-04 jrmu      (flatmap
 6 665c255d 2023-08-04 jrmu       (lambda (j)
 7 665c255d 2023-08-04 jrmu 	(mapcar
 8 665c255d 2023-08-04 jrmu 	 (lambda (k) (list i j k))
 9 665c255d 2023-08-04 jrmu 	 (enumerate-interval 1 (1- j))))
10 665c255d 2023-08-04 jrmu       (enumerate-interval 1 (1- i))))
11 665c255d 2023-08-04 jrmu    (enumerate-interval 1 n)))
12 665c255d 2023-08-04 jrmu 
13 665c255d 2023-08-04 jrmu (defune triples-sum-s (s n)
14 665c255d 2023-08-04 jrmu   "Triples of numbers <= n summing to s"
15 665c255d 2023-08-04 jrmu   (filter
16 665c255d 2023-08-04 jrmu    (lambda (triple)
17 665c255d 2023-08-04 jrmu      (= (sum triple) s))
18 665c255d 2023-08-04 jrmu    (unique-triples n)))