Design of self-checking concurrent error detection systems based on "$2$-out-of-$4$" constant-weight code

The method of Boolean complement is considered for concurrent error detection systems design based on "$2$-out-of-$4$" constant-weight code. Formalized are the rules of computing the Boolean complement functions to transform any operating output vector in concurrent error detection system into "$2$-out-of-$4$" code word. Necessary and sufficient conditions are formulated for controlled logical device to provide the total self-checkability feature of concurrent error detection system.