Properties panels
The Main tab of the Class property panel is used to edit the main information about a class and its basic OWL axioms.
It contains the class name, the main comment field, and sections for class expressions and annotations.
The Name field contains the class name. This is the main identifier of the class in the ontology.
Example: Student
The Comment field represents the first class annotation assertion of type rdfs:comment.
It is used to store a human-readable description of the class. In OWL terms, this corresponds to an AnnotationAssertion axiom whose annotation property is rdfs:comment.
Example:
MandatoryCourse has the comment:
"Mandatory courses are taught by only professors"
This corresponds to: AnnotationAssertion(rdfs:comment :MandatoryCourse "Mandatory courses are taught by only professors")
Each section below contains OWL axioms related to the selected class. A new entry can be added by pressing the + button.
This section contains class expressions that are equivalent to the selected class.
Example:
Professor is equivalent to:
Teacher and facultyLevel value Level_Professor
This means that a class member is a Professor exactly when it is a Teacher whose facultyLevel is Level_Professor.
This section contains superclass axioms of the selected class.
Example:
Student has superclass:
:Person
It also has superclass restrictions:
exactly 1 enrolled value from AcademicProgram at least one takes value from Course
So, in OWLGrEd, the SuperClasses section for Student would include:
Person
enrolled exactly 1 AcademicProgram
takes some Course
This section contains classes that are disjoint with the selected class.
Example:
MandatoryCourse is disjoint with OptionalCourse
This means that no individual can belong to both classes at the same time.
The Keys section is used to define HasKey axioms for the selected class.
A key specifies one or more properties that can be used to uniquely identify individuals of that class. In OWL, this corresponds to a HasKey axiom.
Example:
Person has key: personID
This corresponds to: HasKey(foaf:Person ( :personID ))
Keys dialog
The Keys dialog contains a table where each row represents one property included in the key.
It has the following columns:
Property - the property used as part of the key IsInverse - specifies whether the inverse of the property is used Delete - removes the property from the key definition
The Add button inserts a new row, allowing another property to be included in the same key.
The dialog therefore allows a key to consist of one or several properties.
This section contains other annotations of the class.
These are annotation assertions attached to the class, such as labels, comments, notes, or other metadata.
Each annotation corresponds to an AnnotationAssertion axiom whose subject is the selected class.
Example:
annotation type: comment
value: Mandatory courses are taught by only professors
language: en
This corresponds to an annotation assertion such as:
AnnotationAssertion(rdfs:comment :MandatoryCourse "Mandatory courses are taught by only professors"@en)
To create or edit an annotation, click the + button in the Annotation section. This opens the Annotation dialog.
Annotation dialog
The Annotation dialog contains the following fields:
AnnotationType - the annotation property used for the annotation Value - the annotation value Language - the language tag of the annotation value