assumptions on_floor/1, has/2.


story --> [] ; s, ['.'], story.

s -->  [a, drops], object(O), {+on_floor(O)}.

s -->  anotherAgent(A), [pics,up,something], {-on_floor(X), +has(A,X)}.

object(keys) --> [keys].
object(money) --> [money].

anotherAgent(b) --> [b].
anotherAgent(c) --> [c].


/*********

phrase(story, [a,drops,keys,'.',b,pics,up,something,'.',
               a,drops,money,'.',c,pics,up,something,'.']).

phrase(story, [a,drops,keys,'.',a,drops,money,'.',
               b,pics,up,something,'.',c,pics,up,something,'.']).

**********/