Prime Implicates and Covers
A implicate is a sum term that can cover maxterms of a function.
A prime implicate is a sum term that is not covered by another implicate of the function.
An essential prime implicate is a prime implicate that covers at least one maxterm that is not covered by any other prime implicate.
A set of implicate is said to be a cover of a function if each maxterm of the function is covered by at least one implicate in the set.
A minimal cover is a cover that contains the smallest number of prime implicate and the smallest number of literals..