TELL ==== Syntax: (tell <simple-predication>) ::= (tell [<relation-name> <instance> <value>]) The operator TELL makes it possible to assign new values to the instances for certain relations and to change the knowledge base in this way. Only a simple two-argument-predication can follow after the operator TELL, i.e it is possible to connect a value to a part or characteristic of an instance and in this way change the knowledge base. The pre- dication which follows after TELL has to be full instanciated, there must not be any anonymus- variable instead of a value in this place. The operator TELL returns T, if the operation is executed. NIL will be returned, if the pre- dication is already known, therefore both of the statements will be tested internally with the function EQUAL. If the test is positive, then NIL will be returned. Example: >(tell [place Buckingham-palace London]) T