Define classes as intersections, unions and complements

Intersections and unions can be defined using the modified Manchester OWL Syntax. To create a union or intersection:

• Select a class so that it appears in the Resource Editor
• Click on the downfacing triangle next to rdfs:subClassOf or owl:equivalentClass and select Add empty row (or double-click on owl:equivalentClass to add a row). Type in the name of the class that will participate in the union or intersection, type in the syntax keyword (and or or), type another class name, if needed continue to alternate keywords with class names. Use round brackets to change precedence. While you enter the class expression, you can drag and drop additional class names from the Classes View (or elsewhere).
• To 'commit' the statement, press enter or press the 'OK' icon to the right of the entry line.

A complement class can be created in a similar way. Enter in the owl:equivalentClass widget the syntax keyword not followed by the class name.

Alternatively you can also directly use the owl:unionOf, owl:intersectionOf and owl:complementOf properties instead of using owl:equivalentClass. Right-click on the Class Axioms section on the form to get appropriate input fields, and then enter:

• For unions and intersections use the following syntax: [class1, class2, ..., classN].
• For complements just enter the class name in the owl:complementOf widget.