Patent US 4,020,489

A Friend-Accept decision is made based upon the accumulated value of only a imited number of responses to interrogations. A correct reply causes the accumulated value to increase by a weighted value U.sub.a, while other than a correct response causes the accumulated value to decrease by a weighted value D.sub.b. A decision to accept as a "friend" occurs when the accumulated value reaches or exceeds a predetermined threshold T.sub.a.