Journal of Functional Programming

Articles

Ott: Effective tool support for the working semanticist

PETER SEWELLa1, FRANCESCO ZAPPA NARDELLIa2, SCOTT OWENSa1, GILLES PESKINEa1, THOMAS RIDGEa1, SUSMIT SARKARa1 and ROK STRNIŠAa1

a1 University of Cambridge, Computer Laboratory, William Gates Building, 15 JJ Thomson Avenue, Cambridge CB3 0FD, United Kingdom (e-mail: Peter.Sewell@cl.cam.ac.uk)

a2 INRIA Paris-Rocquencourt, B.P. 105, 78153 Le Chesnay Cedex, France

Abstract

Semantic definitions of full-scale programming languages are rarely given, despite the many potential benefits. Partly this is because the available metalanguages for expressing semantics – usually either for informal mathematics or the formal mathematics of a proof assistant – make it much harder than necessary to work with large definitions. We present a metalanguage specifically designed for this problem, and a tool, Ott, that sanity-checks such definitions and compiles them into proof assistant code for Coq, HOL, and Isabelle/HOL, together with code for production-quality typesetting, and OCaml boilerplate. The main innovations are (1) metalanguage design to make definitions concise, and easy to read and edit; (2) an expressive but intuitive metalanguage for specifying binding structures; and (3) compilation to proof assistant code. This has been tested in substantial case studies, including modular specifications of calculi from the TAPL text, a Lightweight Java with Java JSR 277/294 module system proposals, and a large fragment of OCaml (OCamllight, 310 rules), with mechanised proofs of various soundness results. Our aim with this work is to enable a phase change: making it feasible to work routinely, without heroic effort, with rigorous semantic definitions of realistic languages.

Footnotes

This article is an expansion of a paper presented at ICFP 2007 in Freiburg.