b is a continuant fiat boundary = Def. b is an immaterial entity that is of zero, one or two dimensions and does not include a spatial region as part. (axiom label in BFO2 Reference: [029-001]) Examples: the surface of the skin, the surface of the earth, the surface of the interior of the stomach, the outer surface of a cell or cell wall Definition: An independent continuant [snap:IndependentContinuant] that is a lower dimensional part of a spatial entity, normally a closed two-dimensional surface. Boundaries are those privileged parts of object [snap:Object] entities that exist at exactly the point where the object [snap:Object] is separated off from the rest of the existing entities in the world. Comment: Boundaries are theoretically difficult entities to account for, however the intuitive notion of a physical boundary as a surface of some sort (whether inside or outside of a thing) will generally serve as a good guide for the use of this universal. Synonyms: substance boundary

http://purl.obolibrary.org/obo/BFO_0000140

Examples: the surface of the skin, the surface of the earth, the surface of the interior of the stomach, the outer surface of a cell or cell wall

Definition: An independent continuant [snap:IndependentContinuant] that is a lower dimensional part of a spatial entity, normally a closed two-dimensional surface. Boundaries are those privileged parts of object [snap:Object] entities that exist at exactly the point where the object [snap:Object] is separated off from the rest of the existing entities in the world.

Comment: Boundaries are theoretically difficult entities to account for, however the intuitive notion of a physical boundary as a surface of some sort (whether inside or outside of a thing) will generally serve as a good guide for the use of this universal.

Synonyms: substance boundary

ContinuantFiatBoundary

cf-boundary

b is a continuant fiat boundary = Def. b is an immaterial entity that is of zero, one or two dimensions and does not include a spatial region as part. (axiom label in BFO2 Reference: [029-001])

BFO 2 Reference: In BFO 1.1 the assumption was made that the external surface of a material entity such as a cell could be treated as if it were a boundary in the mathematical sense. The new document propounds the view that when we talk about external surfaces of material objects in this way then we are talking about something fiat. To be dealt with in a future version: fiat boundaries at different levels of granularity.More generally, the focus in discussion of boundaries in BFO 2.0 is now on fiat boundaries, which means: boundaries for which there is no assumption that they coincide with physical discontinuities. The ontology of boundaries becomes more closely allied with the ontology of regions.

BFO 2 Reference: a continuant fiat boundary is a boundary of some material entity (for example: the plane separating the Northern and Southern hemispheres; the North Pole), or it is a boundary of some immaterial entity (for example of some portion of airspace). Three basic kinds of continuant fiat boundary can be distinguished (together with various combination kinds [29

Continuant fiat boundary doesn't have a closure axiom because the subclasses don't necessarily exhaust all possibilites. An example would be the mereological sum of two-dimensional continuant fiat boundary and a one dimensional continuant fiat boundary that doesn't overlap it. The situation is analogous to temporal and spatial regions.

(iff (ContinuantFiatBoundary a) (and (ImmaterialEntity a) (exists (b) (and (or (ZeroDimensionalSpatialRegion b) (OneDimensionalSpatialRegion b) (TwoDimensionalSpatialRegion b)) (forall (t) (locatedInAt a b t)))) (not (exists (c t) (and (SpatialRegion c) (continuantPartOfAt c a t)))))) // axiom label in BFO2 CLIF: [029-001]

Every continuant fiat boundary is located at some spatial region at every time at which it exists

http://purl.obolibrary.org/obo/bfo.owl

continuant fiat boundary

object_boundary

BFO:0000140

continuant fiat boundary

http://purl.obolibrary.org/obo/BFO_0000004

http://purl.obolibrary.org/obo/BFO_0000141