.
                                       D
                              u     u t      u
                            t        y D          t
                          y           u             y
                         D          t    y          D
                         u         D     u          u
                          t          t      y           t
                           y        D    u          y
                            D        t   y          D
                              u        D         u
                                   t     •      t
                                         Y