'map :fs
(dup +) :f1
(dup *) :f2
('f1 fs) :fsf1
('f2 fs) :fsf2

(0 1 2 3) fsf1 puts!
(0 1 2 3) fsf2 puts!
(2 4 6 8) fsf1 puts!
(2 4 6 8) fsf2 puts!