1. A computer system comprising: A. a memory means for storage of data; B. input means for receiving current data being representable as a directed graph; and C. control means for: 1. combining said current data with any existing data in said memory means, said existing data being sequential in nature; 2. determining if a cycle exists in said combined current data and existing data; and, 3. storing in said memory, new data representive of the combined current data and existing data wherein said determined cycle is represented as a single datum point.