SEPARATE (AVL_Trees_Generic)
FUNCTION Height (T: Tree) RETURN Integer IS
------------------------------------------------------------------------
--| Returns the height of a node in an AVL tree
--| Author: Michael B. Feldman, The George Washington University 
--| Last Modified: January 1996                                     
------------------------------------------------------------------------
BEGIN
  IF T = NULL THEN
    RETURN -1;
  ELSE
    RETURN T.Height;
  END IF;
END Height;