AVAILABLE FROM 18.0 SP13
To model a datatype property as a class attribute
- Create a class, name it Class 1.
 - Click on the black circle with the white plus sign in the center of it.
 - Select Property.
 - A default property appears in the class. The property is also called a class attribute.
 - Double - click on the default property. Its Specification window appears.
 - Click on the Type field. A shortcut menu appears. Select boolean. (or any datatype property you want)
 - Click Close.
 
The result should look like this:
The class element with a datatype property unnamed1.

