LP, the Larch Prover — Development History


LP was developed by Stephen J. Garland and John V. Guttag at the MIT Laboratory for Computer Science, a predecessor of CSAIL, the MIT Computer Science and Artificial Intelligence Laboratory. The initial implementation of LP was based on Reve, a rewrite rule laboratory developed by Pierre Lescanne with assistance from Randy Forgaard, David Detlefs, and Katherine Yelick.

Releases

Several versions, distinguished by their release dates, exist for the early releases of LP.

Release 1.0, 1988-1990

The first release of LP extended Reve's term-rewriting system for equational logic to a proof system for quantifier-free first-order logic. It provided

Release 2.0, December 27, 1990

This release contained improvements to the code in Version 1.0. It also provided

Release 2.1, August 21, 1991

This release cleaned up many of the features introduced in Release 2.0 and made them more uniform.

Release 2.2, November 17, 1991

This release provided enhanced deductive mechanisms and better performance. It is the one documented in A Guide to LP, the Larch Prover, by Stephen J. Garland and John V. Guttag, published on December 31, 1991, as Report 82 by the System Research Center of the Digital Equipment Corporation.

Release 2.2a, June 4, 1992

This release provided an experimental implementation of conditional rewriting,

Release 3.1, December 30, 1994

Release 3.1 was a major new release that extended LP's proof system to one for full mulstisorted first-order logic. For more details, see the lists of

Release 3.1a, April 27, 1995

This release fixed some bugs in Release 3.1.

Release 3.1b, September 5, 1997, through January 28, 1999

Release 3.1b was the final official release of LP. It fixed some bugs in Release 3.1a and added a few new features.

Support

LP's development was supported by the following grants from the National Science Foundation and DARPA, the Defense Advanced Research Projects Agency. Additional support was provided by the Systems Research Center of the Digital Equipment Corporation.