Abstract: An interrogating device which includes a rule memory for storing forward inference rules utilizable in a forward inference control system or backward inference rules utilizable in a backward inference control system, a working memory for storing facts, and a forward inference control section for adding or deleting a fact relative to the working memory according to the forward inference rules or a backward inference control section for conducting a search according to the backwad inference rules.

Abstract: An interrogating device includes a memory for storing forward rules and facts, which are used in a forward inference control system, and a control unit operable to add or delete a fact to the memory. In this interrogating device, the accuracy indicates the probability degree of preparation for a conclusion section of the rule. The fact is added to the conclusion section of the rule and is stored in the memory. Also, the accuracy may be used in a strategy for a conflict resolution of a forward inference control. The fact for the accuracy that is obtained in the backward inference has a structure identical to the fact which the accuracy is added for use in the forward inference. By adding the accuracy negatively to the fact and the rule, an inference which uses uncertain data in the forward inference is possible.

Abstract: In a signal transmission system of a key telephone system of the type comprising a main device connected to office lines and having an input/output port for transmitting and receiving signals, and a plurality of key telephone sets connected in parallel to the main device through a pair of signal lines for transmitting and receiving various control signals between the main device and the key telephone sets, wherein each of the control signals is constituted by a pulse width modulated time series signal of a predetermined number of bits, respective control signals are inputted and outputted in parallel to and from a bit input/output of the input/output port and wherein transmission and reception of the control signals between the main device and respective key telephone sets are simultaneously performed by parallel input/output operations of the calculating processing unit.