let l = [1;2;3;4;5];;
let rec mem
list element
= match list with | [] -> false
| head::tail -> if head=element then true else mem tail element
in
Printf.printf
"%B \n" (mem l
3) ;;
bGV0IGwgPSBbMTsyOzM7NDs1XTs7CgoKbGV0IHJlYyBtZW0gbGlzdCBlbGVtZW50ID0gbWF0Y2ggbGlzdCB3aXRoIAoJfCBbXSAtPiBmYWxzZQoJfCBoZWFkOjp0YWlsIC0+IGlmIGhlYWQ9ZWxlbWVudCB0aGVuIHRydWUgZWxzZSBtZW0gdGFpbCBlbGVtZW50CmluClByaW50Zi5wcmludGYgIiVCIFxuIiAobWVtIGwgMykgOzs=