Abstract

Indexing techniques support the retrieval and maintenance of large sets of terms. There is also an indexing method called substitution tree indexing that e ciently handles sets of substitutions. We present three advanced indexing operations for substitution trees: The multi-merge for the simultaneous unification of sets of substitutions, the subsumption operation on two sets of substitutions, and the selection of `lightest' substitutions of a set of substitutions. The indexing operations can be combined to obtain powerful reasoning tools for theorem provers.

Citations