Subkind

Category

RigidSortal

Provides identity

no

Identity principle

simple

Rigidity

rigid

Dependency

optional

Allowed supertypes

Kind, Subkind, Collective, Quantity, Relator, Category, Mixin, Mode, Quality

Allowed subtypes

Subkind, Phase, Role

Forbidden associations

Structuration

Abstract

undefined

Definition

A «Subkind» is a construct used to represent rigid specializations of identity providers («Kind», «Collective», «Quantity», «Relator», «Mode» and «Quantity»). By default, its usage do not require a relational dependency. Let’s see some examples:

Constraints

C1: A «Subkind» must always have exactly one identity provider («Kind», «Collective», «Quantity», «Relator», «Mode», «Quantity») as an ancestor (a direct or indirect super-type). Therefore, our examples in the first figure should be modelled as:

C2: Because it is a rigid type, a «Subkind» cannot have an anti-rigid type («Role», «Phase», «RoleMixin») as an ancestor. Therefore, the following fragments would not be allowed:

C3: Since every instance of a «Subkind» follows the same identity principle, a «Subkind» cannot have an mixin type («Category», «Mixin», «RoleMixin») as a descendant, i.e., a direct or indirect subtype. Fragments like the ones below are not allowed:

Common questions

Q1: Are subkinds only used to specialize kinds?

A1: No! Even though the name might be a little misleading, a «Subkind» may be used to specialize any identity provider, which includes «Collective», «Quantity» and «Relator».

Examples

EX1: Usually, subkinds come in groups, like in the examples below:

EX2: Fragment from the Normative Acts Ontology (see more):

EX3: Fragment of a conceptual model about Brazilian Universities (see more):