/**
 * @description An example of a constraints library
 * @author Joanna Chimiak-Opoka <joanna@opoki.com>
 */	
library constraintlib
	metamodel uml
	require ocl.deflib
	
	public constraints
	context Class
		/**
		 * @description an example of a constraint. Claims that classes have to have at least one attribute	
		 */
		inv numberOfAttributesGreaterThanZero:
			self.numberOfAttributes() > 0
	 endconstraints
	
 endlibrary