Letters to the Editor

On the equivalence of boolean and weighted searching based on the convertibility of query forms

“…The fields of switching rheory and logical design and, more specifically, the branch known as threshold logic can here be called upon, however, t o help solve both of these problems, and, in general, to help examine and explain the Boolean-to-weighted conversion process on a sound mathematical basis (2,3). However, in general, in going from logical combinations to weights which will cause retrieval identical to that of the logical system, one can easily lose sight of the logical combinations actually generated when the weights are assigned on a mere trial and error basis.…”

“…Such common Boolean expressions as A * (B+C) + D * (E+F) cannot be assigned a single set of weights which will provide the desired equivalent weighted form. The fields of switching rheory and logical design and, more specifically, the branch known as threshold logic can here be called upon, however, t o help solve both of these problems, and, in general, to help examine and explain the Boolean-to-weighted conversion process on a sound mathematical basis (2,3). Therefore, brief consideration will first be given to a few of the basic elements of switching theory and threshold logic.…”