Node:Classification of Birds, Next:Inheritance and Delegation, Up:Obj Examples

Classification of Birds

This example illustrates how Prolog object can be used in classification of certain concepts. This style is common in expert system application for describing its domain.

animal :: {
        super(object) &
        relative_size(S) :-
                size(Obj_size),
                super(Obj_prototype),
                Obj_prototype :: size(Prototype_size),
                :(S is Obj_size/Prototype_size * 100)
                }.

bird :: {
        super(animal) &
        moving_method(fly) &
        active_at(daylight)
        }.

albatross :: {
        super(bird) &
        color(black_and_white) &
        size(115)
        }.

kiwi :: {
        super(bird) &
        moving_method(walk) &
        active_at(night) &
        size(40) &
        color(brown)
        }.

albert :: {
        super(albatross) &
        size(120)
        }.

ross :: {
        super(albatross) &
        size(40)
        }.

| ?- ross :: relative_size(R).

R = 34.78