generic
type Element_Type is private;
with function Hash
(Element : Element_Type) return
Hash_Type;
with function Equivalent_Elements
(Left, Right : Element_Type) return
Boolean;
with function "=" (Left, Right :
Element_Type)
return Boolean is <>;
-- ET."=" only used for
Set."="; see p.74.
package
Ada.Containers.Hashed_Sets is ...;