A general method to define quorums

Composition, a general method for constructing quorum sets, coteries, and bicoteries, is discussed. It is shown that composition provides a natural method for constructing quorum structures in an arbitrary network or even in a collection of interconnected networks, and that the resulting structures, called composite structures, can be efficiently evaluated. In particular, an efficient method for determining if a given set contains a quorum of a composite structure is presented. If this method is used, it is not necessary to compute and store all of the quorums of the composite structure in advance.< >