Generating Bijections between HOAS and the Natural Numbers

John Tang Boyland

A provably correct bijection between higher-order abstract syntax (HOAS) and the natural numbers enables one to define a ``not equals'' relationship between terms and also to have an adequate encoding of sets of terms, and maps from one term family to another. Sets and maps are useful in many situations and are preferably provided in a library of some sort. I have released a map and set library for use with Twelf which can be used with any type for which a bijection to the natural numbers exists.

Since creating such bijections is tedious and error-prone, I have created a ``bijection generator'' that generates such bijections automatically together with proofs of correctness, all in the context of Twelf.

In Karl Crary and Marino Miculan: Proceedings 5th International Workshop on Logical Frameworks and Meta-languages: Theory and Practice (LFMTP 2010), Edinburgh, UK, 14th July 2010, Electronic Proceedings in Theoretical Computer Science 34, pp. 21–35.
Published: 11th September 2010.

ArXived at: http://dx.doi.org/10.4204/EPTCS.34.4 bibtex PDF

Comments and questions to: eptcs@eptcs.org
For website issues: webmaster@eptcs.org