;;; -*- logo -*-

to iseq :a :b
if not (:a > :b) [output iseq1 :a :b]
output map [[x] -1 * :x] iseq1 (-1 * :a) (-1 * :b)
end

to iseq1 :a :b
if :a > :b [output []]
output fput :a iseq1 :a + 1 :b
end

bury [iseq iseq1]