ganizations. 


4. the elementary rule is to move one disk if it is possible. Then the
action is extended and controlled by the organization either of disks or of
moves at the different levels by means of several kind inferences that I
have not yet modelized.
chunks are first organised as agregates, then as objects without elements,
then elements are extracted and organised into the whole object. 
Progressively others rules such as move a set of two disks from a peg to
another peg with a single action is co