Multiple Solutions for Problem Reduction -the Aao Algorithm

The A search algorithm nds an optimal path through a search graph. It is easily modi ed to return multiple paths in decreasing order of optimality, but it cannot handle conjunctive problems. The AO search algorithm does handle conjunctive problems and nds an optimal subgraph of an acyclic AND/OR graph. However, it returns only one solution and can only handle totally independent conjunctive problems. This paper describes how a combination of the two algorithms (the AAO algorithm) can be used to return multiple subgraphs of an acyclic AND/OR graph in order of optimality. In addition, it can handle dependencies between conjuncts, but at increased computational cost.