[ovid@tomis data]$ aiprolog spider.pro
Welcome to AI::Prolog v 0.5


?- % no more

?- start.

Enter commands using standard Prolog syntax.
Available commands are:
start.                   -- to start the game.
n.  s.  e.  w.  u.  d.   -- to go in that direction.
take(Object).            -- to pick up an object.
drop(Object).            -- to put down an object.
kill.                    -- to attack an enemy.
look.                    -- to look around you again.
instructions.            -- to see this message again.
halt.                    -- to end the game and quit.

You are in a meadow.  To the north is the dark mouth
of a cave; to the south is a small building.  Your
assignment, should you decide to accept it, is to
recover the famed Bar-Abzad ruby and return it to
this meadow.


start

?- n.
Go into that dark cave without a light?  Are you crazy?
You cannot go that way.n

?-

##</code><code>##

take(Object) :-
  i_am_at(Place),
  at(Object, Place),
  retract(at(Object, Place)),
  assert(at(Object, in_hand)),
  print('OK.'),
  nl.