20. A method as claimed in claim 1 , wherein when no output instructions are found that are associated to the received input stimulus in the data structure, a new received input stimulus is recorded and a new output instruction for producing a response is input in a data structure, the response being taught by a human by providing instructions for producing the response.
20. A method as claimed in claim 1 , wherein when no output instructions are found that are associated to the received input stimulus in the data structure, a new received input stimulus is recorded and a new output instruction for producing a response is input in a data structure, the response being taught by a human by providing instructions for producing the response. 21. A method as claimed in claim 20 , wherein when the output instruction associated with the new received input stimulus is added to the data structure, a level within the hierarchy is allocated and recorded.