enumeration

A library providing tools for building enumeration procedures for recursively- enumerable datatypes. This is built atop the arith-encode library, and makes use of the natural number isomorphisms it provides to represent individual decisions in the enumeration procedure. As such, each enumeration result is denoted by a unique path, consisting of a sequence of natural numbers. An enumeration procedure is simply a (partial) mapping between sequences and a given datatype. The library provides functionality for constructing enumeration procedures, as well as facilities for performing enumeration according to various search strategies (depth-first, breadth-first, etc). These procedures can also be warm-started using a path or a set of paths. Obvious applications include exhaustive search, testing, automated proving, and others. Additionally, as a path is simply a sequence of natural numbers, an enumeration procedure can double as a binary serializer/deserializer. For well-behaved enumeration procedures (ie. those where the mapping is an isomorphism), the resulting binary format should be very nearly succinct. This is the first release candidate for 1.0 (initial release)