into::Ord a => a->[a]->[a]
into x [] = [x]
into x (y : ys)
   |x <= y     = x : y : ys
   |otherwise  = y : into x ys

iSort:: Ord a => [a]->[a] 
iSort []       = []
iSort (y : ys) = into y (iSort ys)

iSort2:: Ord a => [a]->[a] 
iSort2 = foldr into []