class CC [G -> H, H -> G] create set feature set (a_item1: G; a_item2: H) do item1 := a_item1 item2 := a_item2 end item1: G item2: H f local a: detachable ANY do -- H conforms to G. item1 := item2 -- G conforms to H. item2 := item1 -- G conforms to 'detachable ANY'. a := item1 -- H conforms to 'detachable ANY'. a := item2 end end