Boolean prime implicants by the binary sieve method

In the application of Boolean algebra to switching circuits,1,3 one of the areas of interest is that of reduction of the functions to their simplest normal form. Quine, in formulating the special problem of simplification, proposed a method of determining what he called “prime implicants,” and a method of selecting from the prime implicants the “simplest normal equivalents of a formula.𠇔 One of the requirements of this method is that the function first be expressed in �veloped normal form” (standard sum of products or canonical form), each product of the function containing all of the letters of the function. Quine's later method eliminates this requirement.5