code: @Override
  	public boolean hasNextCase() {
  		for (ConstraintWrap wrap : summands) {
  			if (wrap.constraint.hasNextCase()) {
  				return true;
  			}
  		}
  		return false;
  	}
docs: Returns true if one of the sub-constraints still contains mandatory cases
  
  @return true if at least on of the sub-constraints contains at least one mandatory case