Abstract: An approximate reasoning apparatus converts input data into a degree of membership by a membership function, obtains an information quantity for each of a number of factors using the degree of membership, and obtains the possibility of a conclusion using the degree of membership and the information quantities. As a result, the accuracy of an information quantity which prevails at the moment data is entered is taken into consideration to obtain results of reasoning having a high identification capability. Further, a static information quantity of each factor is calculated, the clarity of each factor is obtained from the static information quantity, the clarity of a factor for which data has been entered is calculated from the clarity of each factor, and the finally calculated clarity is displayed as clarity regarding results of reasoning. This makes it possible to judge the reliability of the results of reasoning from the displayed clarity.

Abstract: Improved circuitry for providing bass control in audio playback systems using feedback circuits wherein undesirable deviations in frequency response above the bass region exhibited by previously available Baxandall feedback circuits are substantially eliminated by utilizing, in a preferred embodiment, a voltage follower amplifier, such as an emitter-follower transistor circuit in association with a single capacitance in the bass control circuit, which eliminates the undesirable frequency response deviations at the mid-frequency and higher frequency ranges so that frequency response curves at all settings of the bass control substantially coincide above the bass region.