If we consider a generic function to be a value, it has many functional types and is therefore polymorphic. Parametric polymorphism is referred to as generics. For inheritance, inclusion polymorphism specifies an instance of a subclass can appear wherever an instance of a superclass is required. MI provides an interesting example here, as it is set intersection with an extensional view and set union with an intensional view. Details are left as an exercise for the reader.
Inclusion polymorphism can refer to subtyping, or having at least as much or more than required.
See also section 2.7.