I can not get the following example from the OCaml manual to work:
# let rec sort lst = match lst with  ->  | head :: tail -> insert head (sort tail) and insert elt lst = match lst with  -> [elt] | head :: tail -> if elt <= head then elt :: lst else head :: insert elt tail ;;
^-- this part works so far
# sort l;; - : string list = ["a"; "etc."; "is"; "tale"; "told"]
^-- this is line from OCaml manual. I can’t run this line because the
< in my case seems to force to
int, whereas in the OCaml manual, somehow the
< is polymorphic.
Question: how do I define sort/insert above so that it is polymorphic ? Thanks!
EDIT: forgot actual link: OCaml - The core language