细读OWL的Instance

3. Classes
Classes provide an abstraction mechanism for grouping resources with similar characteristics. Like RDF classes, every OWL class is associated with a set of individuals, called the class extension. The individuals in the class extension are called the instances of the class. A class has an intensional meaning (the underlying concept) which is related but not equal to its class extension. Thus, two classes may have the same class extension, but still be different classes.

When in this document we use wording such as "a class of individuals ..", this should be read as "a class with a class extension containing individuals ...".

NOTE: In OWL Lite and OWL DL an individual can never be at the same time a class: classes and individuals form disjoint domains (as do properties and data values). OWL Full allows the freedom of RDF Schema: a class may act as an instance of another (meta)class.

OWL classes are described through "class descriptions", which can be combined into "class axioms". We first describe class descriptions and subsequently turn to class axioms.

Article 2:
An instance of a class is also an instance of all of its superclasses, ??

OWL API guide:
Named classes can be used to generate individuals. The instances of a class can then be queried using the RDFSClass.getInstances() method:

OWLIndividual individual = brotherClass.createOWLIndividual("Hans");
Collection brothers = brotherClass.getInstances(false);
assert (brothers.contains(hans));
assert (brothers.size() == 1);

Appdx1:设定文字颜色：set text color: jcolorchooser. or jlist has this function