montrealer(jane).
smart(jane).
nerd(jane).
drinks(jane,coffee).

montrealer(bob).
nerd(bob).
drinks(bob,sprite).

owns(teapot,ted).

reader(ted).
reader(mary).
reader(helen).

fatherof(mary,ted).

drinks(helen,sprite).


hasdrug(tea,caffiene).
hasdrug(tea,tannin).
hasdrug(tea,theobromine).
hasdrug(coffee,caffiene).
hasdrug(coffee,oil).
hasdrug(quat,foo).
hasdrug(sprite,sugar).
stimulant(caffiene).
% stimulant(theobromine).


goodstudent(X) :- awakeinclass(X), csstudent(X).
csstudent(X) :- smart(X), (adventurous(X) ; sensible(X)).
adventurous(X) :- ( montrealer(X) ; rockclimber(X) ).
awakeinclass(X) :- drinks(X,Y) , hasdrug(Y,Z), stimulant(Z).
smart(X) :- not(rockclimber(X)), reader(X).
drinks(X,coffee) :- owns(espressomachine,X).
drinks(X,tea) :- owns(teapot,X).

owns(What,Person) :- owns(What,fatherof(Person,Father)).