1. A system for storing and manipulating information in an information base, said system comprising (a) an information storage device; (b) a plurality of information elements stored in said storage device, each information element having at least one attribute with an orderable value, and (c) a topological map stored in said storage device for each said attribute, said map comprising (1) means for representing a predetermined number of ranges of attribute values, which ranges collectively include the attribute values for all information elements in the information base; and (2) means defining a correspondence between each of said information elements and the ranges to which they map.