The new AI::Prolog is on its way to the CPAN. This is mostly a bugfix releasen and I've included a new min-game "sleepy.pro".
0.71 Sat June 25, 2005
Removed _failgoal in Engine.pm. We now backtrack if we need
new results.
Added several new regression tests.
Fixed bug where code was not warning on unknown predicates.
(Doug Wilson)
Fixed bug where tracing fails when it tries to print a non-
existent "next_clause". (Doug Wilson)
retract/1 now works correctly. (Doug Wilson)
Fixed unification bug that crept in in .62.
Added data/sleepy.pro, a game that wasn't working because of
the retract/1 bug.