When you describe a constraint element the element_name consists of two parts separated by two hyphens.
Each part represents one of the algorithms the constraint is imposed on.
depending on the subelement the constraint is imposed on.
Also you should specify the constraint type parameter (currently the only available type is distance):
And specify one of the distance types, for example:
Example1: The constraint is imposed on myORF and myPattern algorithm elements:
Example2: The constraint is imposed on myORF algorithm element and the left myRepeats algorithm subelement:
The available constraint elements are described in the Constraint Elements chapter.