Weighting Method for the Determination of the Irredundant Set of Prime Implicants

A complete or restricted set of prime implicants (PI´s) can cover the terms of the switching function with more or less redundancy. In order to find an irredundant form from the set of PI´s, it is necessary to choose those PI´s which contribute most effectively towards the strict minimum sum. The criterion for the right choice of the PI´s is their weight from the point of view of their cost and their ability to cover a maximum number of switching terms. This criterion assures the simplicity of the switching circuit and helps to increase its reliability. The PI´s with the highest weight are chosen.