(* <pre> *)

val pwd = OS.FileSys.getDir;
val cd = OS.FileSys.chDir;

Control.Print.printDepth := 50;
Control.Print.printLength := 50;

cd "D:/work/sheard/courses/PsuCs321/web/notes";

fun lastone x = hd (rev x)
fun prefix x = rev (tl (rev x))

fun mymap f [] = []
  | mymap f (x::xs) = (f x):: (mymap f xs);

fun filter p [] = []
  | filter p (x::xs) =
     if (p x) then x :: (filter p xs) else (filter p xs);

(* </pre> *)