ACL2 works on the Unix (and some variants, including Linux), Macintosh, and Windows 98 operating systems. It is built on top of any of the following Common Lisps: Allegro, GCL (Gnu Common Lisp) [or, AKCL], Lispworks, Lucid, and MCL (Macintosh Common Lisp). Support for Windows 98 is relatively new, and has undergone only minimal testing with Allegro Common Lisp. So, we would appreciate any feedback if there are problems. We expect that ACL2 may run on other Microsoft Windows operating systems using Common Lisp implementations other than Allegro, but we have not made such a try; please let us know if you try ACL2 on such platforms.
(Old remark, potentially obsolete for most users:) We have successfully run a
small but nontrivial test suite on a Sparc 2 with 16 megabytes of main memory,
but performance appears better with more memory. For more on this, see Problems.
tar xpvf acl2.tar
gunzip solaris-7-sparc-saved_acl2.tar.gz tar xpvf solaris-7-sparc-saved_acl2.tar rm solaris-7-sparc-saved_acl2.tar mv solaris-7-sparc-saved_acl2 acl2-sources/saved_acl2 chmod a+x acl2-sources/saved_acl2
gunzip debian-gnu-linux-saved_acl2.tar.gz tar xpvf debian-gnu-linux-saved_acl2.tar rm debian-gnu-linux-saved_acl2.tar mv debian-gnu-linux-saved_acl2 acl2-sources/saved_acl2 chmod a+x acl2-sources/saved_acl2
By default, if no
LISP=xxx is specified,
LISP=gcl is used. On our hosts,
gcl is the name of
GNU Common Lisp. You can fetch GCL without fee from
or from mirror sites listed at
Linux notes. We have successfully built ACL2 under Debian Gnu Linux with GCL 2.3, and have been told by GCL author Bill Schelter that GCL 2.3.6 works with Redhat 6.1 and 6.2. One user has found GCL 2.3 (as opposed to 2.3.6) satisfactory with Redhat 6.1, while another experienced rare problems with Redhat 6.2 using GCL 2.3 that went away with GCL 2.3.6.
The time taken to carry out this process depends on the host processor but may be only several minutes for a fast processor (by June 2000 standards). The size of the resulting binary image is dependent on which Lisp was used, but it may be in the vicinity of 17 megabytes.
make works for the Common Lisps listed in Requirements above. It may only work on Sun
Sparcs and 486/66 PCs, for all we know about the portability of Unix
Makefile code. See the file
acl2-sources/Makefile for further details. If this
make command does not work for you, please see the
instructions for non-Unix systems below.
You can now skip to Using ACL2.
Open an ftp connection to
ftp.cs.utexas.edu by anonymous login and ftp
to the local
acl2-sources subdirectory all of the files
and directories in and below the ftp directory
pub/moore/acl2/v2-5/acl2-sources. You may link to our
ftp sources directory by clicking
You will find that
contains many files, subdirectories, sub-subdirectories, etc. We mean
for you to copy over to your local connected directory the entire
structure of files and subdirectories. Thus, when this ftp operation
is done, your local connected directory should have a subdirectory
acl2-sources and it should contain (at some level)
everything obtained by the ftp. Your local
subdirectory will now look exactly as though you had obtained our
acl2.tar.gz and done the
rm steps of the Unix instructions.
Next we describe how to create a suitable binary image containing
ACL2. This takes some time and you are urged first to find out
(perhaps from a local Common Lisp authority) how to save the resulting
image so that it does not have to be constructed from scratch each
time you wish to use ACL2. The time taken to carry out the
initialization process depends on the host processor but may be an
hour or two. The size of the resulting binary image is dependent on
which Lisp was used, but it may be in the vicinity of 17 megabytes.
See the file
mcl-acl2-startup.lisp for Macintosh
Invoke your local Common Lisp, which should be one of those listed in
Requirements above. Filenames in this
Lisp session should default to the dir
directory, e.g., for GCL, connect to
/acl2-sources before invoking GCL or, after
entering GCL, do
Now skip to "Building ACL2 under Windows 98" below for instructions for building ACL2 on Windows-based systems. Otherwise, read on.
Then type the following sequence of Lisp commands,
(load "acl2.lisp") (in-package "ACL2") (compile-acl2)
The commands above will compile the ACL2 sources and create compiled
object files on your
acl2-sources subdirectory. Now exit
your Common Lisp and invoke a fresh copy of it (mainly to avoid saving
an image with the garbage created by the compilation process). Again
arrange to connect to the
acl2-sources subdirectory. In the fresh
(load "acl2.lisp") (in-package "ACL2") (load-acl2) (initialize-acl2)
This will load the new object files in the Lisp image and bootstrap
ACL2 by reading and processing the source files. But the attempt at
initialization will end in an error! The message will say that it is
impossible to finish because a certain file was compiled during the
processing, thus dirtying the image yet again. So now exit your
Common Lisp and invoke a fresh copy of it (again arranging to connect
acl2-sources subdirectory). Then, in the fresh
(load "acl2.lisp") ; (load "acl2-init.lisp") ; if to use our save (in-package "ACL2") (quick-compile-acl2 t t) (initialize-acl2)
This will load the new object files into the Lisp image, and bootstrap ACL2 by reading and processing the source files. This run will succeed and leave you at the top level of your Lisp.
If you were to invoke
(LP) now, you will enter the
ACL2 command loop as discussed in Invoking
ACL2. However, we recommend that instead of doing this you save
the current image to an executable file using whatever save mechanism
exist in your Common Lisp. For consistency with these installation
instructions, we suggest you save the binary image to the file named
/acl2-sources/saved_acl2. The function
save-acl2 in file
acl2-init.lisp shows how
we save an image in various Common Lisps.
You may now proceed to Using ACL2.
nsaved_acl2if it exists.
acl2-sourcesdirectory and submit the following sequence of commands.
(load "acl2.lisp") (in-package "ACL2") (compile-acl2)The commands above will compile the ACL2 sources and create compiled object files on your
acl2-sourcessubdirectory. In the fresh Lisp type:
(load "init.lsp") (in-package "ACL2") (load-acl2) (initialize-acl2 (quote include-book) *acl2-pass-2-files* t t)This will load the new object files in the Lisp image and bootstrap ACL2 by reading and processing the source files. But the attempt at initialization will end in an error! The message will say that it is impossible to finish because a certain file was compiled during the processing, thus dirtying the image yet again.
acl2-sourcessubdirectory). Then, in the fresh Lisp type:
(load "init.lsp") (in-package "ACL2") (save-acl2 (quote (initialize-acl2 (quote include-book) *acl2-pass-2-files* t)) "saved_acl2")You have now saved an image. Exit Lisp now. Subsequent steps will put the image in the right place.
osaved_acl2if it exists.
saved_acl2.dxlboth exist THEN:
saved_acl2.dxl(at end of line) to
nsaved_acl2.dxlshould exist; move it to
acl2-sourcesmay be found in the file
all-files.txtin that directory.
README.html; This file acl2-sources/ LICENSE ; GNU General Public License Makefile ; For Unix make. See README. TAGS ; Handy for looking at source files with emacs *.lisp ; ACL2 source files. all-files.txt ; List of all files in this directory and subdirectories books/ ; Examples, potentially useful in others' proofs. See books/README.html. doc/ ; ACL2 documentation in various formats emacs/ ; Miscellaneous emacs and file utilities, not well documented init.lsp ; Useful for building the system. interface/ emacs/ ; Support for ACL2 "proof trees". See interface/emacs/README.doc. infix/ ; ACL2 infix printer by Mike Smith. See interface/infix/README. saved/ ; Empty directory for backing up copies during make; not important acl2.tar.gz; gzip'd tar file containing all of acl2-sources/ (see below) acl2.tar.gz.SUM ; result of our running sum acl2.tar.gz images/ ; Some gzip'd tar'd executables; see images/README. split/ ; The result of splitting up acl2.tar.gz; see split/README
The entire acl2.tar.gz is roughly 6.5 megabytes, which expands out to roughly
22 megabytes. Additional space is required to build an image, perhaps 17
megabytes (though this depends on the Lisp), and to certify books.
acl2.tar.gzfile in order to build acl2. That file includes more than just the ACL2 sources proper. It suffices, for building ACL2, via the instructions above, to fetch only the
acl2-sources/*.lispfiles, which take up `only' about 5 megabytes, together with the files
acl2-sources. The sources and an executable image are located on that subdirectory. The executable image is called
acl2-sources/saved_acl2. You can invoke ACL2 by running that image, e.g.,
/usr/local/bin/acl2, containing the following two lines:
When you invoke ACL2, you should see the host Common Lisp print a header concerning the ACL2 version, license and copyright.
Some hosts then automatically enter the ACL2 ``command loop,'' an ACL2 read-eval-print loop with the prompt:
ACL2 !>Other hosts will leave you in Common Lisp's read-eval-print loop. If yours is one of the latter, evaluate the Common Lisp expression
(LP)if the current package is
Once in the ACL2 command loop, you can type an ACL2 term, typically followed by ``return'' or ``enter,'' and ACL2 will evaluate the term, print its value, and prompt you for another one. Below are three simple interactions:
ACL2 !>t T ACL2 !>'abc ABC ACL2 !>(+ 2 2) 4
To get out of the ACL2 command loop, type the
This returns you to the host Common Lisp. We sometimes call this
``raw Lisp.'' You may re-enter the command loop with
(LP) as above.
Note that when you are in raw Lisp you can overwrite or destroy ACL2 by executing inappropriate Common Lisp expressions. All bets are off once you've exited our loop. That said, many users do it. For example, you might exit our loop, activate some debugging or trace features in raw Lisp, and then reenter our loop. While developing proofs or tracking down problems, this is reasonable behavior.
Now you are ready to test your image.
An easy way to test the theorem prover is to type the following term to the ACL2 command loop:
:mini-proveallThis will cause a moderately long sequence of commands to be processed, each of which is first printed out as though you had typed it. Each will print some text, generally a proof of some conjecture. None should fail.
A more elaborate test is to certify the ``books'' that
come with the distribution.
acl2-sources/books/README.htmlfor information. The general topic of books is discussed thoroughly in the ACL2 documentation; see the
BOOKSnode in the documentation tree.
Books should be ``certified'' before they are used. We do not distribute certificates with our books, mainly because certification produces compiled code specific to the host. You should certify the books locally as a test of your ACL2 image.
It is easy to re-certify all the distributed books in Unix. We recommend you do this. If you have entered ACL2, exit to the operating system, e.g., by control-d in many systems.
While connected to dir
make certify-booksThis will generate minimal output to the screen and will probably take an hour or two. To remove the files thus created, invoke:
make certify-books has been constructed so that it
will certify the books that you are most likely to want to use in your work
(with the ACL2 form
include-book). However, you can certify all
the books, including books for the case studies described in the (hardbound)
Reasoning: ACL2 Case Studies, using the command:
By default, certification uses the image
/acl2-sources/saved_acl2. You may specify any ACL2
image, as long as it is either a command on your Unix path or an absolute file
name, for example as follows.
make certify-books ACL2=my-acl2 make certify-books-all ACL2=/u/smith/projects/acl2/saved_acl2
We apologize to non-Unix users: we do not provide non-Unix
instructions for recertifying the distributed books. The
certification methods provided by the authors of the books vary
greatly and we codified them in the Unix Makefile used above. Most
acl2-sources/books contain either a
README file or a
certify.lsp file. Users
who wish to certify one of these books and who cannot figure out (from
these scant clues) what to type to ACL2 should not hesitate to contact
Next proceed to the section on Documentation.
ACL2's documentation is a hypertext document that, if printed in book form, is about 800 pages or about 1.5 megabytes of text. Its hypertext character makes it far more pleasing to read with an interactive browser. The documentation is available in four formats: HTML, Texinfo, Postscript and ACL2 documentation strings. All of this material is copyrighted by the University of Texas at Austin and is derived under the GNU General Public License from material copyrighted by Computational Logic, Inc.
Two Web-based guided tours of ACL2 are available from the home page
noted below. If you are already familiar with Nqthm, you might find
it useful to look at the documentation node
NQTHM-TO-ACL2. Another useful documentation topic for
beginning ACL2 users is the node
The ACL2 Home Page is
The home page provides a selected bibliography, guided tours of the system, and the complete hypertext documentation tree.
Once you have installed ACL2, the HTML form of the documentation is
available locally as
We urge you to browse your local copy of the documentation rather than our Web copy, simply to reduce Web traffic and the demand on our server.
This is a very convenient format for accessing the ACL2 documentation from within Emacs. In Emacs, invoke
meta-x infoand then, if you are unfamiliar with Info, type
control-h mto see a list of commands available. In particular, type
* ACL2 i.j: (dir
Documentation for ACL2 version i.j.
acl2-sources/doc/texinfo.texwhich is copyrighted by the Free Software Foundation, Inc. (See that file for copyright and license information.)
The Postscript version of the documentation is not included in our normal distribution because it is so much less useful than the hyper-text versions. But a gzipped Postscript (1MB) version is available. It prints as a book of almost 900 pages and contains a Table of Contents and an index to all documented topics.
ACL2 Documentation Strings
The ACL2 system has facilities for browsing the documentation. However this
requires that the documentation be stored as strings in the Lisp image. To
save space, the images mentioned so far in this document do not contain
resident documentation strings. To build such an image on a Unix system,
make large LISP=xxx
while connected to the
acl2-sources directory. The
xxx above should be replaced by the name of your local Common
Lisp. (By default, if no
LISP=xxx is specified,
LISP=gcl is used. On our hosts,
gcl is the
name of GNU Common Lisp.) This will create dir
(note that this is the same name previously used for the image without
documentation strings). The new image may be 30 megabytes in size and
take several minutes to build on a fast (in June 2000) machine.
For non-Unix systems, the ``large'' image can be built in your local Common
(load "acl2.lisp") (in-package "ACL2") (compile-acl2 nil) (load-acl2 nil) (initialize-acl2 'include-book *acl2-pass-2-files* nil)Non-Unix users should then save the image to an executable binary file.
Once you have an image of ACL2 containing documentation strings, and you are in
the ACL2 command loop, you may query the documentation on a given topic
by typing the command
where topic is the Lisp symbol naming the topic you want to learn about. To learn more about the on-line documentation, type
:help and then return.
This completes the installation of ACL2 Version 2.5. You may wish to
return to the Table of Contents.
gettimes out, an alternative is to get all of the many files in the directory
split/, each of which matches the pattern
split-acl2.tar.gz*(e.g., using an `mget' command). Once you have got all these files, concatenate them together in alphabetic order, e.g., with the command
cat split-acl2.tar.gz* > acl2.tar.gz
If you are using Version 3.2.0 of Lispworks, there is probably a bug
in the definition of
logeqv. Harlequin has sent us a
patch; if anyone asks us for it, we will ask Harlequin if we may
forward their patch.
If you are running on GCL or AKCL on a machine with only 16 megabytes
of RAM, it may be a good idea to have a file
~/acl2-init.lsp containing the following form, which will
help to keep the ACL2 process small as you are running it:
(setq acl2::*acl2-allocation-alist* nil).In one test several years ago, we found the following times (minutes:seconds) using a Sparc 2.
31:42 64 megabytes main memory 33:37 64 megabytes main memory, using the SETQ form above 63:52 16 megabytes main memory 43:09 16 megabytes main memory, using the SETQ form above
If you are running Linux Slackware v3.0:
#+gcl (setq COMPILER::*SPLIT-FILES* 100000)This way the lisp compiler splits large C source files in files of about 100K. Without this line, some systems do not have enough memory to compile the C files. (We saw this problem arise on a machine with 16Mb of actual memory plus 16Mb of virtual memory.)
Thanks to Vanderlei Moraes Rodrigues for the Slackware notes.
REALfor information about this extension and how to build it, and a warning about its experimental nature.
firstname.lastname@example.org. The body of the message should contain the line:
To send a message to all who receive ACL2 mail, send the message to
email@example.com. You can post messages to the ACL2 mailing
list only if you are a member of the list.
Finally, please report bugs in ACL2 to
This version of ACL2 is a descendent of ACL2 Version 1.9, Copyright (C) 1997 Computational Logic, Inc.
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
Matt Kaufmann (Kaufmann@cs.utexas.edu)
J Strother Moore (Moore@cs.utexas.edu)
Department of Computer Sciences
University of Texas at Austin
Austin, TX 78712-1188 U.S.A.