Another trouble spot in ALGOL60

A creep control valve for keeping vehicle brakes applied is under the control of a digital electronic system which senses the vehicle speed and whether the accelerator pedal is depressed or released. The creep control is enabled only after the vehicle speed is between 3 and 24 miles per hour and then drops below 6 miles per hour with the accelerator pedal released. The creep control is disabled whenever the accelerator pedal is depressed or the vehicle speed is above 6 miles per hour or there is a failure of the speed resolver which senses the vehicle speed. The creep control includes a key-operated anti-theft circuit which keeps the brakes on if an incorrect key is inserted.