ACL2 Version 8.3 ACL2 is a logic and programming language in which you can model computer systems, together with a tool to help you prove properties of those models. "ACL2" denotes "A Computational Logic for Applicative Common Lisp". ACL2 is part of the Boyer-Moore family of provers, for which its authors have received the 2005 ACM Software System Award.

Welcome to the ACL2 home page! We highlight a few aspects of ACL2:

Libraries (Books).

Libraries of books (files containing definitions and theorems) extend the code that we have written. In particular, the distribution tarball includes the community books , which are contributed and maintained by the members of the ACL2 community.

Libraries of (files containing definitions and theorems) extend the code that we have written. In particular, the distribution tarball includes the , which are contributed and maintained by the members of the ACL2 community. Documentation.

There is an extensive user's manual for the ACL2 system, and an even more comprehensive manual that documents not only the ACL2 system but also many community books. See below to learn more.

There is an extensive user's manual for the ACL2 system, and an even more comprehensive manual that documents not only the ACL2 system but also many community books. See below to learn more. License and Copyright.

ACL2 is freely available under the terms of the LICENSE file distributed with ACL2. License, copyright, and authorship information is available from the ACL2 documentation.

ACL2 is freely available under the terms of the LICENSE file distributed with ACL2. License, copyright, and authorship information is available from the ACL2 documentation. Extensions.

The ACL2 distribution includes the following extensions, which were developed by the individuals shown. NOTE: Not included in this list is what was formerly known as "ACL2(h)", because it is now the default build of ACL2: that is, ACL2 builds are now hons-enabled. Thanks to Bob Boyer, Warren A. Hunt, Jr., Jared Davis, and Sol Swords for their contributions; see the acknowledgments. ACL2(r)

Support for the real numbers by way of non-standard analysis

Ruben Gamboa ACL2(p)

Support for parallel evaluation

David L. Rager Another extension of ACL2 is the Eclipse-based ACL2 Sedan (ACL2s). Unlike the systems above, ACL2s is distributed and maintained by Pete Manolios and his research group. ACL2s comes with a standard executable ACL2 image for Windows, but it also comes with pre-certified community books and an extension of ACL2 with additional features, including extra automation for termination proofs as well as counterexample generation.

The ACL2 distribution includes the following extensions, which were developed by the individuals shown. Not included in this list is what was formerly known as "ACL2(h)", because it is now the default build of ACL2: that is, ACL2 builds are now hons-enabled. Thanks to Bob Boyer, Warren A. Hunt, Jr., Jared Davis, and Sol Swords for their contributions; see the acknowledgments. Another extension of ACL2 is the Eclipse-based ACL2 Sedan (ACL2s). Unlike the systems above, ACL2s is distributed and maintained by Pete Manolios and his research group. ACL2s comes with a standard executable ACL2 image for Windows, but it also comes with pre-certified community books and an extension of ACL2 with additional features, including extra automation for termination proofs as well as counterexample generation.

DARPA

National Science Foundation This material is based upon work supported by the National Science Foundation under Grant Nos. CCF-1526760, CNS-1525472, CCF-1153558, EIA-0303609, CNS-0429591, ISS-0417413, CCF-0945316, and CNS-0910913. Any opinions, findings and conclusions or recomendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.

Advanced Micro Devices, Inc.

ForrestHunt, Inc.

Rockwell Collins, Inc.

Sun Microsystems, Inc.

The ACL2+Books Manual includes not only the ACL2 User's Manual, but also documents many of the community books (libraries). This manual, which is written by many authors, is thus more extensive than the ACL2 system, and is thus potentially more useful. With the exception of the first bulleted link below, links to the manual on this page will all take you to the ACL2+Books Manual.

The following links take you to these two manuals. The manuals can however be read not only in a Web browser, but in the ACL2-Doc Emacs browser or by using the ACL2 :DOC command at the terminal; see the documentation topic, DOCUMENTATION .

Once you have installed ACL2, you can browse the ACL2 User's Manual locally by viewing a copy of this home page under your ACL2 sources directory at doc/home-page.html and following the last link shown above; but first you will need to run the following command in your ACL2 sources directory.

make DOC ACL2=<path_to_your_ACL2>

Better yet, you can build the ACL2+Books Manual locally, as follows, though this will likely take longer (perhaps a half hour or more, depending on which books you have already certified).

cd acl2-sources/books # The following uses ccl by default; sbcl is also acceptable. make manual ACL2=<path_to_your_ACL2>

books/doc/manual/index.html





We strongly encourage users to submit additional books and to improve existing books. If you have interest in contributing, there is a documentation topic to get you started. You can also visit the ACL2 System and Books project page on github (just move past the big list of files to find descriptive text). Project members are welcome to edit community books. In particular, the community book books/system/doc/acl2-doc.lisp contains the ACL2 system documentation, and project members are welcome to improve it.

We also distribute a few interface tools. For these, see the Utilities section of Books and Papers about ACL2 and Its Applications. Some of the papers mentioned in that collection contain utilities, scripts, or ACL2 books for the problem domains in question.

