Table 3. Three foundational types of spatio-topological relations between material entities.

Type of material entity	Relation between its parts	Type of inner boundary separating its parts	Characteristics
object or fiat object part	topological coherence	fiat boundarymat between fiat object parts	Coherence implies physical continuity and qualitative homogeneity within the object or fiat object part
object cluster	topological adherence	bona fide boundary between objects	Adherence implies physical continuity and qualitative heterogeneity within the object cluster
object group	metric proximity	bona fide boundary and fiat boundaryimmat between objects	Metric proximity implies physical separation through spatial gaps between the constitutive objects of the object group