attract pt POINT_INSIDE ->             attract pt POINT_OUTSIDE ->
  ...                                    ...
_                                      _
  pt : point                             pt : point
;                                      ;


attract pt POINT_OUTSIDE_X ->          attract pt POINT_OUTSIDE_Y ->           attract pt POINT_OUTSIDE_Z ->
  ...                                    ...                                     ...
_                                      _                                       _
  pt : point                             pt : point                              pt : point
;                                      ;                                       ;



attract pt POINT_OUTSIDE_XY ->         attract pt POINT_OUTSIDE_XZ ->          attract pt POINT_OUTSIDE_YZ ->
  ...                                    ...                                     ...
_                                      _                                       _
  pt : point                             pt : point                              pt : point
;                                      ;                                       ;

