1. generic 
  2.  
  3.    type Element       is private; 
  4.    type Index         is (<>); 
  5.    type Element_Array is array (Index range <>) of Element; 
  6.  
  7.    with function "<" (Left, Right : Element) return Boolean is <>; 
  8.  
  9. procedure Concurrent_Mergesort (Sort_Field : in out Element_Array);