cookie.pl

action([], _).
action([cat|Rest],s(Jar)) :- print('Can I haz cookie?'), nl, action(Rest,Jar).
action([cat|Rest],empty) :- print('No cookie? Meow!'), nl, action(Rest,empty).
action([monster|Rest],empty) :- print('Cookie monster is sad'), nl, action(Rest,empty).
action([monster|Rest],_) :- print('Om nom nom'), nl, action(Rest,empty).
action([granny|Rest],Jar) :- print('You look skinny dear, here, have some cookies'), nl, action(Rest,s(s(s(s(s(Jar)))))).

run(Actions) :- action(Actions,empty).  

test :- run([granny, monster,cat,monster,granny,cat,monster]).