Intelligent Agents for Lisp / News: Recent posts

Release 3.2

Fixed a nasty bug that made the TEST conditional element non-functional. Thanks to Aneil Mallavarapu for reporting this. Releases 3.0 and 3.1 are basically worthless. Get this one.

Posted by David E. Young 2007-09-17

Release 3.1

A bugfix release for 3.0. Relatively minor stuff, but you should upgrade for your sanity.

Posted by David E. Young 2007-09-11

Release 3.0

First new release in awhile. Support for SBCL; two major bug fixes affecting performance; etc. See the ChangeLog for details.

Posted by David E. Young 2007-09-08

Release 2.4

A minor release that makes Lisa compatible with CLISP 2.38.

Posted by David E. Young 2006-02-21

Release 2.3

Patch by Fred Gilham that enables auto-notify support for CMUCL.

Posted by David E. Young 2005-07-30

Release 2.2

This release contains a fix for a major bug in lisa's join network. Thanks to Andy Sloane for the work and the patch.

Posted by David E. Young 2005-07-30

Release 2.1

This is the official 2.1 release. There have been no changes since the cvs beta version.

Posted by David E. Young 2005-04-04

2.1 beta (and CF)

2.1 beta is available. This version has preliminary support for Certainty Factors, as described in PAIP. It needs testing, and I don't consider it definitive. There's also a streamlined build available via asdf; see the release notes.

There's a readme for CF in the lisa root directory (CF-README).

Posted by David E. Young 2004-09-17

Uncertainty and Lisa

Upon request, I've decided to look into adding support for certainty factors (cf). It's been suggested I build a generic facility that supports the three most popular representations of cf; since my time is limited, I think I'll start with the model described in PAIP and work on that. After that has been evaluated by the Lisa community, I'll consider adding other implementations.

Posted by David E. Young 2004-09-13


The development version now uses ASDF rather than MK:DEFSYSTEM. This is in the cvs repository now and will make it into the next release.

Ease of building and loading has been improved.

Posted by David E. Young 2004-06-09

Release 2.0.7

Another bug-fix release. This one fixes the "rule after facts" problem reported by Aneil Mallavarapu.

Posted by David E. Young 2004-06-06

2.0.6 Released

Version 2.0.6 is available. This is a bugfix release, addressing problems with duplicate fact detection and truth maintenance. Thanks to Aneil Mallavarapu for the patches.

Posted by David E. Young 2004-03-08

2.0.5 Released

Release 2.0.5 is now available. This is a bug-fix distribution that addresses problems with Lisa's taxonomic reasoning mechanism. Thanks to Aneil Mallavarapu for finding the problem and offering a solution.

Posted by David E. Young 2003-11-01


Minor changes to the debugger. See RELNOTES.html for details.

Posted by David E. Young 2003-05-28


LISA 2.x apparently no longer runs on CMUCL, due to incompatibilities between LISA's use of the MOP and its implementation within CMUCL. I currently do not have access to a Linux box in order to investigate the problem, but according to the CMUCL folks the trouble seems to be in PCL. I've no plans to address this issue in the near future, but if someone wants to investigate and send a patch that would be nice.

Posted by David E. Young 2003-04-09

2.0.3 ready

Latest bug-fix release, addressing a problem with queries. Thanks to Push Singh for the report.

Posted by David E. Young 2002-12-20

Release 2.0.2 ready

2.0.2 is a bug-fix release for 2.0. This version fixes a bug in the Rete network that prevented identical patterns from occuring consecutively within the same rule.

Posted by David E. Young 2002-12-09

2.0 Production available

LISA's first 2.0 production release is available. Details are in the usual places, but of special note is the new Auto Notification feature.

Posted by David E. Young 2002-12-04

2.0 Beta 3 ready

More major enhancements, including contexts (similar to modules or rule packets) and duplicate fact detection. The release notes in the distribution should be consulted for details, along with the reference guide.

Posted by David E. Young 2002-11-23

2.0 Beta 2 ready

Beta 2 is out. Lots of changes, including a full implementation of truth maintenance (negated patterns are now supported). Check the release notes and documentation for details!

Posted by David E. Young 2002-11-16

2.0 beta 1 ready

LISA 2.0's first beta is available. New to this release are truth maintenance and a few bug fixes.

Posted by David E. Young 2002-11-05

2.0a5 ready

The latest 2.0 alpha is available. This version introduces the OR conditional element, along with enhancements to the debugger.

Posted by David E. Young 2002-11-02

2.0a4 ready

Alpha 4 is ready. New to this release is the LISA debugger, an interactive production rule monitoring/inspection facility. Pretty basic right now, but one can set breakpoints in rules, examine the token stack, look at variable bindings and their values, single step into rules, etc. I'll add new features if and when requests come in.

Posted by David E. Young 2002-10-27

2.0a3 available

Probably the last alpha release for 2.0. I've added the remaining missing 1.x features (watches and embedded DEFRULEs). Dean is working on truth maintenance, which should be in the next feature release. When that'll be, I don't yet know.

Posted by David E. Young 2002-10-19

2.0 Alpha 2 available

The second alpha release for 2.0 is out. New to this version are queries, rule redefinition, and improved MODIFY and ASSERT macros.

Posted by David E. Young 2002-10-17