INCLUSION CRITERIA
An entry belongs in this subdivision if and only if its intended models are spatial—regions, points, or extended bodies—and its primitives are relations among them.
Required: At least one of the following:
- A qualitative calculus of region relations with a composition table or constraint semantics (RCC, Allen-style over space, cardinal direction calculi)
- A mereotopological theory combining parthood with connection or contact
- A logic whose accessibility or interpretation is spatial (topological, metric, or region-based) and whose subject is space rather than the modality
Not sufficient: A topological semantics deployed to interpret a non-spatial modality (that belongs in Modal—the topology is apparatus there, not subject). A temporal interval calculus (Modal/Temporal), even though the relation algebra is the same shape. Mereology as a bare theory of parthood without a spatial or topological primitive (Theories).
Boundary: Spatial logics whose individuation is the modal apparatus—topological semantics for □, with space as the intended reading—live in Modal/Alethic and are cross-listed here. The qualitative calculi, whose content is the relation set and its composition, live here. Mereotopology sits on the seam: the parthood half is a theory, the connection half is spatial, and it is placed here because the connection primitive is what it adds.