--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/configurationengine/doc/rule.rst	Thu Mar 11 17:04:37 2010 +0200
@@ -0,0 +1,76 @@
+Rule
+====
+
+	A Configuration can contain rule's, which can be aplied to the :class:`~cone.public.api.Configuration` 
+	:class:`~cone.public.api.Feature`'s. In ConE a single rule will create an instance of :class:`~cone.public.plugin.Relation`. 
+	
+	The textual format of a rules is always of form:
+	::
+	
+	  <left side> relation_name <right side>.
+
+The rule dialect
+----------------
+	
+	The features are accessed in the left and right side of the rule with the default :class:`~cone.public.api.View` of the :class:`~cone.public.api.Configuration`. 
+	Basically ConE will get the default_view and use the :class:`~cone.public.api.ObjectContainer` member access to retrieve the feature.
+	There are few special characters that are converted to function calls in the rule transformation.
+	
+	* ``*`` => refers to all immediate childer of this node, which is transformed to method call :meth:`cone.public.api.ObjectContainer.__objects__`
+	* ``**`` => refers to all childer of this node, which is transformed to method call :meth:`cone.public.api.ObjectContainer.__traverse__`
+	
+	Both sides of the rule are something that the :class:`~cone.public.plugin.Relation` will somehow evaluate. How the left 
+	side and right side are evaluated, is basically specific to the implementation of the :meth:`~cone.public.plugin.Relation.execute` 
+	method of the :class:`~cone.public.plugin.Relation`. However certain basic evaluation rules apply to all :class:`~cone.public.plugin.Relation` objects.
+	
+	When a feature is referred, ConE will try to return the value of the feature. 
+	Then the Relation tries to evaluate if the given feature is bound and evaluates as True.
+	
+	So for example referring to a feature.
+	
+	``group.fea1`` is the same as writing ``group.fea1==True`` for a boolean feature.
+	``group.intfea1`` is the same as writing ``group.fea1!=0`` for a integer feature.
+	
+	If a feature is unbound, trying to access its value will raise UnboundError. 
+
+Boolean logic in rules
+----------------------
+	
+		Both left and right side of the rule can contain normal boolean algebra that is utilized in the evaluation. This uses 
+		default python syntax for boolean logic, with keywords *and*, *or*, *not*.
+
+Example of boolean logic
+^^^^^^^^^^^^^^^^^^^^^^^^  
+::
+	a.b and c.d=10 depends (not a.b.x=10 or a.b.x=0)
+
+
+
+
+Rules with different multiplicity
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+	The above mechanism enables that the rules can define relations with different multiplicity. 
+	
+	* one-to-one
+	
+		* e.g. A depends B
+	
+	* one-to-many
+	
+		* e.g. A depends B.*, which is basically the same as wrinting A depends (B.child1 and B.child2 and ..)
+		* e.g. A depends B and C
+	
+	* many-to-one
+	
+		* e.g. A.* depends B
+	
+	* many-to-many
+	
+		* e.g. A.* depends B.*
+
+Examples
+--------
+	
+	* A.B.C requires A.B.D
+	* fea.group.* requires fea.group
+	* wlan.setting maps voip.setting=10