ACL2 Version 8.1 Installation Guide

Easy Install for Unix-like Systems

Here, "Unix-like Systems" includes Unix, GNU-Linux, and MacOS X. Note that a quicker and even easier install may be possible, by instead obtaining a pre-built binary distribution if one is available for your platform. Otherwise, you can follow the directions below, which start by fetching a file hosted at the github ACL2 System and Books website. The result is a directory containing not only the ACL2 system but, in the books/ subdirectory, the community books (libraries). The ACL2 system is developed at the University of Texas at Austin and can also be obtained or explored separately.

Connect to a directory whose full pathname contains no whitespace and which does not already contain a subdirectory named acl2-sources or acl2-8.1. Then use either of the following two methods to obtain the ACL2 source code and community books.
- (Recommended if you don't plan to update from git)
  Fetch gzipped tar file acl2-8.1.tar.gz from GitHub and then execute:
  tar xfz acl2-8.1.tar.gz
  This will create a subdirectory named acl2-8.1. Connect to acl2-8.1.
- (Development snapshot, required if you want to update from GitHub: generally should be fine, but on rare occasions may be incomplete, fragile, or unable to pass the usual regression tests)
  Execute:
  git clone https://github.com/acl2/acl2 acl2-sources
  This will create the subdirectory acl2-sources. Connect to acl2-sources/.

Obtain a Common Lisp implementation if you don't already have one.

Type:
```
make LISP=<path_to_your_lisp_executable>
```
This will create a script in your connected directory for running ACL2. The script is named saved_acl2.
Note: You will need Gnu make. We have seen problems on some Linux systems with Version 3.81 of that utility, so if you encounter errors, please consider our instructions for downloading and installing GNU make version 3.80.

Certify books, for example with
```
make certify-books
```
or something fancier such as the following:
```
(time nice make -j 8 ACL2=/u/smith/bin/acl2 certify-books) >& make-certify-books.log
```
This may take less than 2 hours or much longer (perhaps 8 hours, perhaps even more), depending on your machine and host
Common Lisp. The resulting log file, make-certify-books.log, should contain no occurrences of the string ``CERTIFICATION FAILED''; a normal exit (status 0) should guarantee this. If you want additional explanation and further options (e.g., about perhaps avoiding root login), see the documentation for BOOKS-CERTIFICATION; for example, use of the target, basic, as in
```
cd books ; make -j 8 ACL2=<path_to_acl2> basic
```
will take considerably less time (perhaps as little as 5 minutes instead of several hours) than using the target certify-books.

You now have an ACL2 executable called saved_acl2 (from step 3) and access to certified community books (from step 4). Enjoy!

THE ABOVE INSTRUCTIONS MAY BE ALL THAT YOU NEED. Otherwise, read on....

More Information

Note: To build variants of ACL2, see the documentation topic REAL for ACL2(r) and COMPILING-ACL2P for ACL2(p).