Ontological Nature
A Class carries a restrictedTo array listing the ontological
natures its instances may have — the fundamental UFO categories that its individuals fall under.
An instance of a class restricted to functional-complex is a functional whole such as a person or
a car; an instance of a class restricted to event is an occurrence such as a soccer match.
This is a closed enumeration: restrictedTo is an array whose entries must each be one of the
eleven tokens below. A validator rejects any other value.
- JSON type:
string[]— an array of enum strings. - Constraint: each entry is one of the eleven tokens listed below.
Values
| Nature | Meaning | Example |
|---|---|---|
functional-complex | Objects whose parts play distinct functional roles. | Person, Car |
collective | Wholes whose parts play a uniform role. | Deck of Cards, Forest |
quantity | Portions of matter or stuff. | Water Portion, Gold Portion |
relator | Extrinsic aspects existentially dependent on two or more endurants. | Marriage, Employment |
intrinsic-mode | Aspects depending only on their bearer. | an intention, a skill, a symptom |
extrinsic-mode | Externally dependent modes. | a commitment, a love |
quality | Measurable aspects projected into a quality structure. | Weight, Color, Temperature |
event | Perdurants / occurrents that unfold in time. | Soccer Match, Birth |
situation | Configurations of entities that obtain at a time. | Checkmate, Settled Debt |
type | High-order types whose instances are themselves types. | Ship Type, Dog Breed |
abstract | Entities outside space-time. | Number, Set, Proposition |
Named subsets
Several rules in OntoUML — in particular the constraints on relation ends — refer to groups of these natures by name rather than one by one. The three nested subsets below are the most common.
| Subset | Members |
|---|---|
| substantial | functional-complex, collective, quantity |
| endurant | substantial ∪ relator, intrinsic-mode, extrinsic-mode, quality, type |
| concrete individual | endurant ∪ event, situation |
These subsets are nested: every substantial nature is an endurant, and every endurant is a
concrete individual. The remaining token, abstract, lies outside all three — abstract entities
are neither endurants nor perdurants.
Examples
A sortal class such as «kind» Person restricts its instances to a single nature:
"restrictedTo": ["functional-complex"]
A non-sortal class such as a «category» may generalize instances of several natures, in which case
restrictedTo lists more than one token:
"restrictedTo": ["functional-complex", "relator"]
Which natures are appropriate depends on the class's stereotype. See
Class Stereotypes for the restrictedTo values expected for each standard
stereotype (for example, relator classes are restricted to ["relator"], while non-sortals take a
non-empty subset of the natures).