/* puzzle program  */

alpinist(tony).
alpinist(mike).
alpinist(john).

climber(X) :- alpinist(X),~skier(X).

~likes(X,rain) :- climber(X).
~likes(mike,X) :- likes(tony,X). 
likes(mike,X) :- ~likes(tony,X).
likes(tony,rain).
likes(tony,snow).

~skier(X) :- ~likes(X,snow).

wanted(X) :-alpinist(X),climber(X),~skier(X).

/*  goal: wanted(X)  */