16. The method of claim 15, wherein the decomposition comprises the steps of: selecting a constituent model referenced by the lower-level cell; determining whether the shape model in the selected cell maintains a rain relationship with the constituent model; and determining whether the constituent model is a shape model.
16. The method of claim 15, wherein the decomposition comprises the steps of: selecting a constituent model referenced by the lower-level cell; determining whether the shape model in the selected cell maintains a rain relationship with the constituent model; and determining whether the constituent model is a shape model. 19. The method of claim 16, wherein in the event that the shape model in the selected cell maintains a rain relationship with the constituent model and the constituent model is not a shape model, the method further comprises the step of performing a decomposition upon the shape model in the selected cell and the constituent model.