Symbolic Logic Problem-Solving Software
For The Macintosh

Bertrand18.sit is a compressed, StuffIt archive containing a fully functional copy of Bertrand (version 1.8), the Bertie font, a license agreement, a brief manual ("Read Me"), and a folder of example problems.

As of 9/25/2003, Bertrand is FREEWARE and OPEN SOURCE. I strongly encourage programmers to improve Bertrand, and/or to port it to another operating system, especially OS X native. For information on how to obtain the source code, contact me at

Be sure to install the Bertie font before running Bertrand. Bertrand will not run without it.

Download Bertrand18.sit [368K]. This version of Bertrand runs on PowerPCs and on 680x0 Macs in native mode. It has been tested on System 9.2.2 and on OS X (10.1.3 - 10.4.2), but should be compatible with systems dating back to 8.1 (and perhaps further).

Improvements in current version 1.8: Bertrand now can solve problems in the background. The user can freely access other programs, and work with all other aspects of Bertrand (including saving and printing files), while it is solving a problem. Optimization levels can now be changed "on the fly". Added "Branches Closed" line in the Routine Window. Fixed bug that caused premise files saved out of opened tree files to cause a file system error when opened. Many other internal improvements.

Improvements in version 1.7: Added a user-settable "halting factor" and improved the way Bertrand interprets trees in which the halting factor comes into play. Significantly increased algorithm speed (up to 10 times on trees with many branches, especially with Optimization off). Fixed bug that caused Bertrand sometimes to crash on trees with more than 256 branches. Finally, while Bertrand is still shareware, new users no longer need to obtain a registration code in order to print and save problems.

Download the Bertie font suitcase[80K]. This is the font truetype used by Bertrand (included with Bertrand18.sit, above).

Download BertrandReadMe.pdf [80K]. This is the short manual included with Bertrand.sit, above.

Bertrand Home Page.