. 


3.2 Generic goals. 
A number of observations allow me to give an inventary of different types of
goals (we'll see that later). 
A generic goal is a goal uttered one time with a general form, without
specification in the current state. so it can be applied several times when
the current state allows it.
A specific kind is the general goal which can appear either to bring every
disks to the goal peg, that is to say that first one have to bring disk 2,
then after disk 3, and only after disk 4 to peg c, an