Aleksey Nogin, Alexei Kopylov, Xin Yu, and Jason Hickey
A Computational Approach to Reflective Meta-Reasoning about Languages
with Bindings.
In MERLIN '05: Proceedings of the 3rd ACM SIGPLAN workshop on
Mechanized reasoning about languages with variable binding, pages 2--12.
ACM Press, 2005.
An extended version is available as California Institute of Technology
technical report CaltechCSTR:2005.003.
ACM Digital Library
Entry, CaltechCSTR Entry,
PDF, PS
We present a foundation for a computational meta-theory of languages with bindings implemented in a computer-aided formal reasoning environment. Our theory provides the ability to reason abstractly about operators, languages, open-ended languages, classes of languages, etc. The theory is based on the ideas of higher-order abstract syntax, with an appropriate induction principle parameterized over the language (i.e. a set of operators) being used. In our approach, both the bound and free variables are treated uniformly and this uniform treatment extends naturally to variable-length bindings. The implementation is reflective, namely there is a natural mapping between the meta-language of the theorem-prover and the object language of our theory. The object language substitution operation is mapped to the meta-language substitution and does not need to be defined recursively. Our approach does not require designing a custom type theory; in this paper we describe the implementation of this foundational theory within a general-purpose type theory. This work is fully implemented in the MetaPRL theorem prover, using the pre-existing NuPRL-like Martin-Löf-style computational type theory. Based on this implementation, we lay out an outline for a framework for programming language experimentation and exploration as well as a general reflective reasoning framework. This paper also includes a short survey of the existing approaches to syntactic reflection.
Last update: Tuesday, October 25, 2005 by Aleksey Nogin (e-mail: nogin+web@cs.caltech.edu)