If P is a part of object Q, and Q is a part of object R, > then P is a part of object R > > D1: > P is an ingredient of an object Q when and only when, > P is the same object as Q or is a part of object Q > > D2: > P is the class of objects p, when and only when the > following conditions are fulfilled: > > a) > P is an object > > b) > every p is an ingredient of object P > > c) > for any Q, if Q