OPMES: A similarity search engine for mathematical content

Abstract

This paper presents details about a new mathematical search engine, i.e., OPMES. This search engine leverages operator trees in both representation and relevance modeling of the mathematical content. More specifically, OPMES represents mathematical expressions using operator trees, and then indexes each expression based on all the leafroot paths of the generated operator tree. Such data structures enable OPMES to implement an efficient two-stage query processing technique. The system first identifies structurally relevant expressions based on the matching of the leaf-root paths, and then further ranks them based on their symbolic similarity to the query.