May 1999 (version 2.1):
Object modules are now printed out using their name instead of their definition.
demo_fails has been renamed to fails and features the following improvements:
It's more general, especially for what concerns = and dif constraints.
It can handle correctly disjunction and parameterization of function symbols.
It interacts correctly with preds_ definitions.
There is a garbage collector that takes care of removing useless pending constraints.
NOTICE: This version of fails is stable and works correctly in at least all cases covered by its predecessor demo_fails, but it is still under improvement and a new, perfected version is expected soon.
Switches are available for activating and disactivating the extended syntax and the output of the garbage collection.
ground_ is now correctly defined.
The manuals have been updated to reflect the changes.
New examples concerning the implementation of Event Calculus have been added.
December 1998 (version 2.0), first release.