AI-NeuralNet-Simple-0.03 $ aiprolog 


Welcome to AI::Prolog v 0.732
Copyright (c) 2005, Curtis "Ovid" Poe.
AI::Prolog comes with ABSOLUTELY NO WARRANTY.  This library is free software;
you can redistribute it and/or modify it under the same terms as Perl itself.

Type '?' for help.

?- help('retract/1') 

retract/1

    Remove facts from the database. You cannot remove rules. This may
    change in the future. See assert(X).

     retract(loves(ovid,java)).

help(retract/1) 

Yes
?-