Abstract: To make validity of a prediction model created by machine learning be able to be verified with appropriate accuracy and efficiency. A software test apparatus includes a storage device configured to store a prediction model, and an arithmetic device. The arithmetic device is configured to accept inputs of a precondition, a constraint condition, and an approximation threshold value, convert the prediction model into a logical expression, analyze an approximation range based on the approximation threshold value with respect to the logical expression to simplify the logical expression, generate an inspection expression by combining the simplified logical expression with the precondition and negation of the constraint condition, search for, as a counterexample, a value satisfying the inspection expression, input the value to the prediction model to evaluate inspection accuracy when the counterexample exists, and output a result of the evaluation.

Abstract: In a data communication system, a plurality of personal computers are connected through respective terminal adapters to a telephone line. Each terminal adapter includes a communication control section, a storage section and a network control unit (NCU). The communication control section includes a central processing unit (CPU), a read only memory (ROM) and a modulator-demodulator or modem. The terminal adapter has a power supply independent of a power supply of the personal computer so that power can be applied to the terminal adapter even when the personal computer is not connected to the power supply. The terminal adapter can automatically receive a mail regardless of the status of the personal computer. The received mail is stored in the storage section of the terminal adapter. When a recipient reads the received mail, the personal computer is started up and a key board connected to the personal computer is operated in accordance with a menu.

Abstract: A cursor display system causes a cursor to move on a screen in the same direction as that of a pointing device, such as a mouse, operated by an operator viewing the screen, even if the display on the screen is inverted, i.e. turned round through 180 degrees. To display the cursor, which is moved by operating the pointing device, on a display device which is capable of inverting the display on the screen, a display status holding device is provided for memorizing whether the screen displayed on the display device is in a normal status or in the inverted status. The display status holding device is connected to a changeover device for changing data of operating directions supplied from the pointing device depending on the status memorized by the display status holding device.

Abstract: A plurality of resistors connected in a ladder format and disposed in parallel with each other. Each of the resistors has a resistance part and two mutual connection ends connected to the resistance part. The mutual connection ends are gathered at one side with respect to the resistance part.