MODULE Deep;
IMPORT Out;
CONST N = 10;
TYPE
  Point = RECORD x, y: INTEGER END;
  Node = POINTER TO NodeDesc;
  NodeDesc = RECORD key: INTEGER; left, right: Node END;
VAR
  pt: Point;
  n: Node;
  i: INTEGER;
PROCEDURE Walk(t: Node);
BEGIN
  IF t # NIL THEN Walk(t.left); Walk(t.right) END
END Walk;
BEGIN
  NEW(n);
  n.key := 5; n.left := NIL;
  pt.x := 1; pt.y := 2;
  WHILE i < N DO INC(i) END;
  CASE i OF
    1..3: Out.Int(i, 0)
    | 4, 5: Out.Char("x")
  ELSE
    Out.Ln
  END;
  Walk(n)
END Deep.