Generating Essential Primes for a Boolean Function with Multiple-Valued Inputs

Detecting essential primes is important in multiple-valued logic minimization. In this paper, We present a fast algorithm that can generate all essential primes without generating a prime cover of the Boolean function. A new consensus operation called asymmetric consensus (acons) is defined. In terms of acons, we prove a necessary and sufficient condition for detecting essential primes for a Boolean function with multiple-valued inputs. The detection of essential primes can be performed by using a tautology checking algorithm. We exploit the unateness of a Boolean function to speed up tautology checking. The notion of unateness considered is more general than that has appeared in the literature.