a class or group of items which share a unique combination of critical attributes not shared by other groups, and can be referred to by the same generic name or symbol

a common feature or characteristic

a general property that we judge different particular objects to share

an identity of a group of objects, events that share some common characteristics

a set of function declations, contract clauses, and local type declarations which describe a class

a set of objects or events that share common characteristics and a common name

a symbol which represents a class of objects or acts

As well as objects used for rendering a 3D scene, Q supplies a generalized Knowledge Base. The Knowledge Base consists of a network of Concepts which can be connected together using relationships to assert facts. For example, if we have the Concepts "fido", "max" and "dog", we can use the built-in Concept "isa" to construct the relationships "fido isa dog" and "max isa dog". We can then use the Q APIs or the QDS tool to query the Knowledge Base, e.g. if we perform the query "isa dog" then we will find all of the Concepts that satisfy the relationship, i.e. "fido" and "max". This very generic structure can be used to construct complex relationships between objects, e.g. to store properties of an object. Each heavy (persistent) Q object has a corresponding Concept. class, P81

A term to define a class of objects. The "unit of symbolic processing" [Manchester University Medical Informatics Group] in a medical terminology.

The definition of a type of objects or events. A concept has an intensional definition (a generalization that states membership criteria), and an extension (the set of its instances).

Concept is a construct consisting of one object class and one reference class. The object class is a conventional class as defined in object-oriented programming and hence a concept without a reference class (with the empty reference class) is equivalent to a class. Each concept has one parent concept, called superconcept, which is specified in its declaration via concept inclusion relation.