Prolog

6. Consider this database of facts, describing what something is made up of.

has(bicycle,wheel,2).

has(bicycle,handlebar,1).

has(bicycle,brake,2).

has(wheel,hub,1).

has(bicycle,frame,1).

has(car,steering_wheel,1).

has(car,stereo,1).

Write a predicate partof(X,Y) that succeeds if Y is part of X.

?- partof(wheel,spoke).

True.

?- partof(bicycle,spoke).

True.

?- partof(car,spoke).

False.

partof(X,Y) can also be used to enumerate the parts that make up an object or of which an object is part of.

?- partof(bicycle,X).

X = wheel;

X = handlebar;

X = break;

X = frame;

X = hub;

?- partof(X,spoke).

X = wheel;

X = bicycle.