% vehicles.pl
% Little database of vehicles; queries include truck(X), watervehicle(X), and
% vehicle(X).

typeof(bmw,car).
typeof(chevy,car).
typeof(chevy,truck).
typeof(ferrari,car).
typeof(mack,truck).
typeof(car,landvehicle).
typeof(truck,landvehicle).
typeof(sunfish,sailboat).
typeof(hunter,sailboat).
typeof(chriscraft,powerboat).
typeof(powerboat,boat).
typeof(sailboat,boat).

truck(X) :- typeof(X,truck).
watervehicle(X) :- typeof(X,sailboat); typeof(X,powerboat).
vehicle(X) :- watervehicle(X),!; typeof(Y,landvehicle), !.