class A [G] create make feature make (v: G) is do g := v if v /= Void then att_g := v end det_g := v create l1 create l2 create l3 create l4 create l5 create l6 create l7 create l8 create l9 end feature g: G att_g: !G det_g: ?G l1: B [G] l2: B [?G] l3: B [!G] l4: ?B [G] l5: ?B [?G] l6: ?B [!G] l7: !B [G] l8: !B [?G] l9: !B [!G] end