Figure 1. Compositional and spatial partitions.

A. A compositional partition of bona fide objects that are situated in a nested fashion (constitutional hierarchy; see Fig. 2) within bona fide objects of a coarser granularity, which in their turn are, again, situated within bona fide objects of an even coarser granularity. A compositional partition always yields objects that are demarcated exclusively by bona fide boundaries. B. A spatial partition of the same constitutively organized bona fide object into an object aggregate and a fiat object part. C) A spatial partition of a bona fide object resulting in two fiat object parts, one of which in its turn is spatially partitioned again, resulting in two other fiat object parts. Fiat boundary ^mat : demarcates fiat parts of a material entity; fiat boundary ^immat : demarcates fiat parts of an immaterial entity (i.e. a hole).