1. A programmable logic module for a programmable logic device which includes an interconnection conductor network for conveying signals to, from, and/or between a plurality of logic modules on the device comprising: circuitry configured to produce an output signal which the circuitry is controllable to select from either of two selections, a first of the selections being an output signal which is any of a plurality of logical combinations of four input signals applied to the circuitry from the interconnection conductor network, and a second of the selections being an output signal which is derived from any one of four input signals applied to the circuitry from the interconnection conductor network and selected by other input signals applied to the circuitry from the interconnection conductor network.