You can still give a name to the interface. However, interfaces apply to modules, not to types. In Ocaml you'd say "this module implements the Comparable interf

You can still give a name to the interface. However, interfaces apply to modules, not to types. In Ocaml you'd say "this module implements the Comparable interface" while in an OO languague you'd say "this type is a subtype of Comparable". Sorry for the confusion.