How to Create a Restriction

Restrictions are entered through the table in the Restriction Definitions pane of the Ontology Editor, thus:

• Add a new restriction by clicking on the New button, this will create a new entry in the table.

• Then double click on it to edit its name to something more appropriate.

• Now set the type of the restriction by double clicking on its "Type" cell, this brings up a window with a hierarchy of current restrictions and basic types, (see How to Set the Type of an Attribute for details). Facts can not be chosen as a type.

• Now double click on the "Restriction" cell, this opens a small green panel through which the default value can be typed. The syntax will be dependent on the type chosen previously.

The restriction will be syntactically checked upon entry, invalid entries will be displayed in red. The syntax of restrictions is that of a simplified expression, details of which are provided here.