TERMINAL FAULT TESTS FOR THRESHOLD FUNCTIONS.

A method is presented for finding the Boolean difference of a threshold logic function that requires solving linear inequalities. The linear inequalities can also be used to find all minimal true vertices and maximal false vertices of the threshold function. It is shown that a true input combination of the Boolean difference with respect to the input having minimal weight can be easily modified to find a true input combination of the Boolean difference with respect to any input. This collection of input combinations leads to a set of (n plus 1) tests for detecting any multiple terminal s-a-0(1) fault of an n-variable threshold function. For the case of unidirectional faults, the procedure simplifies, and only four tests are required to detect all unidirectional terminal faults of a majority function.