This defines, simply enough, Thing as a SuregenObject (the top class) with colour and height as attributes.
P_PrepareMeal is - somewhat outside the range of intended applications -defined as a SuregenProcess with an internal attribute named SP (= subprocesses). The :are keyword ensures that instances of the respective classes P1_buyFood, P2_cook and P3_setTable are generated for every new instance of P_PrepareMeal (provided that the classes exist at instantiation time).