The order of a rule group is roughly the same as the maximal number of root nodes in rule tests which have different types. For each order loop node needs a range decaration , i.e. a specification to which node set the node is instantiated. The most simple case is if the range of an order loop node is just one parameter node. Then the range declaration can be omitted, if the variable is specified in the parameter list. If the range of the order loop node is a set or a graph node domain, a range declaration , i.e. a declaration to which graph node domain or node set the order loop node is initialized.
Ranges can refer to user specified parameters or to automatically generated parameters.