12. A probabilistic learning element as described in claim 11, wherein a tree structure used to store objects of learned states includes at each node thereof an object that is a part of a state whereby the tree includes sequences of objects shown in context.
12. A probabilistic learning element as described in claim 11, wherein a tree structure used to store objects of learned states includes at each node thereof an object that is a part of a state whereby the tree includes sequences of objects shown in context. 13. A probabilistic learning element as described in claim 12, wherein each node of the tree has stored therein the number of occurrences of the object in the context represented by the node.