Reduced Implicate Tries and Logical Operations

The reduced implicate trie (ri-trie), introduced in (Murray and Rosenthal, 2005), is a target language for knowledge compilation. It has the property that any query can be processed in time linear in the size of the query. In this paper, conjunction and negation are developed as update operations for ri-tries that do not require recompilation. Conjunction has been implemented, and experimental results, though preliminary, are promising. Conjoining a formula to an existing ri-trie by compiling the new formula and conjoining the tries is generally more efficient than compiling the conjunction of the two formulas.