**February 2012**. Magnus verified the soundness of the Milawa
kernel in HOL4, and connected it to the correctness proof for
Jitawa,
his verified Lisp runtime. Milawa is thus proved *sound
all the way down to the machine code!*. For more on this project
(including source code), see Magnus's
Jitawa
page and also my Milawa on Jitawa
page.

Milawa is a "self-verifying" theorem prover for an ACL2-like logic.

We begin with a simple proof checker,
call it *A*, which is short enough to verify by the "social
process" of mathematics—and more recently with a theorem prover
for a more expressive logic.

We then develop a series of increasingly powerful proof checkers, call them
*B*, *C*, *D*, and so on. We show each of these programs
only accepts the same formulas as *A*, using *A* to verify
*B*, and *B* to verify *C*, and so on. Then, since we
trust *A*, and *A* says *B* is trustworthy, we can trust
*B*. Then, since we trust *B*, and *B* says *C*
is trustworthy, we can trust *C*. And so on for all the rest.

Our final proof checker is really a theorem prover; it can carry out a
goal-directed proof search using assumptions, calculation, rewrite rules, and
so on. We use this theorem prover to discover the proofs of soundness for
*B*, *C*, and so on, and to emit these proofs in a format that
*A* can check. Hence, "self verifying."

Milawa is free software released under a permissive MIT/X11 style license.

Milawa has changed since my dissertation; the links and instructions here lead to the most recent version. An archive of the "original" Milawa web site is also available, which for instance includes compressed versions of the original, pre-generated proofs, and full proof-checker output, logs, etc.

The current version of Milawa is now distributed as part of the ACL2 Books project.

Milawa isA full build includes

- An ACL2 sketch of Milawa's soundness proof
- A user interface for developing Milawa proofs and translating ACL2 proofs into Milawa
- Bootstrapping to use Milawa to discover its soundness proof

You can also browse the file listing from the web server without downloading anything. This listing does not include any of the proof files, certifications, logs, etc., which are available in the archived version, because I am no longer doing my development from this directory.

- Magnus Myreen and Jared Davis.
*The reflective Milawa theorem prover is sound (down to the machine code that runs it)*. To appear in ITP 2014. July, 2014. Slides from my July 2012 talk at Northeastern University - Magnus Myreen and Jared Davis.
*A verified runtime for a verified theorem prover*. ITP 2011.

*A self-verifying theorem prover*

Ph.D. thesis, University of Texas at Austin

December 2009.

PDF paper, 2 MB

Errata*A self-verifying theorem prover*

Ph.D. defense

September 18, 2009

PDF slides; 352 KB

*The Milawa rewriter*

and an ACL2 proof of its soundness

Not published

October 5, 2007.

PDF paper, 202 KB*A trustworthy, extensible theorem prover*

Ph.D. dissertation proposal

October 22, 2007

Screen version (PDF, 305 KB)

Print version (PDF, 305 KB)

(Also a technical report: The University of Texas at Austin, Department of Computer Sciences, Report #TR-08-14, March 2008. [link])

*The Milawa rewriter*

and an ACL2 proof of its soundness

PDF slides; 580 KB

November 16, 2007 (ACL2 '07)*A trustworthy, extensible theorem prover*

Ph.D. dissertation proposal

PDF slides; 961 KB

AVI movie with commentary; 16 MB, 19 minutes

October 24, 2007*Tactics and tracing*

PDF slides; 550 KB

ACL2 seminar, March 28, 2007*Adding a computation rule*

PDF slides; 387 KB

Also available as a WMV movie; 88 MB, 67 mins

ACL2 seminar, August 2, 2006*Designing a trustworthy, extensible theorem prover*

PDF poster; 350 KB

Gradfest, March 2006*Milawa: an extensible proof checker*

PDF slides; 760 KB

ACL2 seminar, November 16, 2005

Contact: jared@cs.utexas.edu

This material is based upon work supported by the National Science Foundation under Grant No 0429591. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

This material is based upon work supported by the Defense Advanced Research Projects Agency (DARPA) under Contract NBCH30390004.