indexing description: "Objects that may be compared according to a partial order relation" names: part_comparable, comparison deferred class interface PART_COMPARABLE feature -- Comparison infix "<" (other: like Current): BOOLEAN -- Is current object less than other? require other_exists: other /= void infix "<=" (other: like Current): BOOLEAN -- Is current object less than or equal to other? require other_exists: other /= void infix ">" (other: like Current): BOOLEAN -- Is current object greater than other? require other_exists: other /= void infix ">=" (other: like Current): BOOLEAN -- Is current object greater than or equal to other? require other_exists: other /= void invariant -- from GENERAL reflexive_equality: standard_is_equal (Current); reflexive_conformance: conforms_to (Current); end -- class PART_COMPARABLE