(setq mat (multi-rnd-ornament 3 5 r1 s1 :seed 0.1))
->(((a -b a) (b a b) (-b -c) (c b) (b a b a) (a -b) (-c -d -c) (d e) (-b a -b) (c d c) (a b) (b c) (c b c) (-b a) (-d -e) (e d) (b a) (a -b a) (-c -d) (d e) (a -b a)) ((2/5 2/5 1/5) (9/16 9/32 9/32) (21/40 7/20) (15/16 5/16) (9/32 9/32 9/32 9/32) (1/3 2/3) (3/8 3/16 3/16) (11/12 11/24) (7/32 7/16 7/32) (1/2 1/2 1/4) (1/2 1/2) (9/10 9/40) (5/16 5/8 5/16) (7/20 21/40) (5/12 5/24) (9/8 3/8) (3/8 3/4) (1/2 1/4 1/4) (1/2 1/4) (33/32 11/32) (2/5 2/5 1/5)))
(setq new-mat (apply-on-which '(a) s1 (car mat)
r1 (cadr mat)))
->(((a -b a) b -b c b (a -b) -c d -b c (a b) b c -b -d e b (a -b a) -c d (a -b a)) ((2/5 2/5 1/5) 9/8 7/8 5/4 9/8 (1/3 2/3) 3/4 11/8 7/8 5/4 (1/2 1/2) 9/8 5/4 7/8 5/8 3/2 9/8 (1/2 1/4 1/4) 3/4 11/8 (2/5 2/5 1/5)))
or
(setq new-mat2 (apply-on-which '(7/8 9/8) r1
(cadr mat) s1 (car mat)))
->((1/1 (9/16 9/32 9/32) (21/40 7/20) 5/4 (9/32 9/32 9/32 9/32) 1/1 3/4 11/8 (7/32 7/16 7/32) 5/4 1/1 (9/10 9/40) 5/4 (7/20 21/40) 5/8 3/2 (3/8 3/4) 1/1 3/4 11/8 1/1) (a (b a b) (-b -c) c (b a b a) a -c d (-b a -b) c a (b c) c (-b a) -d e (b a) a -c d a))