1. The section of a digital computer that carries out instructions in proper sequence, interprets each coded instruction, and applies the proper signals to the arithmetic unit and other parts in accordance with this interpretation.

2. A mathematical check used with some computer operations.

A means or device to direct and regulate a process or sequence of events.

An input element of a cryotron.

1. A test made to determine the extent of error in experimental observations or measurements.

2. A procedure carried out to give a standard of comparison in an experiment.

3. Observations made on subjects which have not undergone treatment, to use in comparison with observations made on subjects which have undergone treatment.