using Nemerle.IO;

 class P { }

class C : P { }

interface I {
  boo () : P;
}

abstract class Ab : I {
  public abstract boo () : C;
}

class B : Ab {
  public override boo () : C { 
    print ("B:boo\n");
    null 
  }
}

class AA {}
class BB : AA {}

interface J {
  foo (x : BB) : AA;

  hoo (x : int) : object;
}

class OO : J {
  public foo (_x : AA) : BB { 
    print ("OO:foo\n");
    null 
  }
  public hoo (x : object) : int { 
    print ("OO:hoo ");
    print (x.ToString ());
    print ("\n");
    1
  }
}

module M { 
  Main () : void {
    def x = B() : I;
    _ = x.boo ();
    def x = OO () : J;
    _ = x.foo (null);
    print (x.hoo (4).ToString ());
    print ("\n");
  }
}


/*
BEGIN-OUTPUT
B:boo
OO:foo
OO:hoo 4
1
END-OUTPUT
*/