结果没有与给定的事实进行比较

Question

使用 prolog 编写代码来获得一些比较输出，但有些输出无法正常工作。似乎那些与事实不符。这里是代码

fact(Fact) :- Fact,!.
fact(Fact):-Fact = ..[Rel, Arg1, Arg2],isa(Arg1, SuperArg).
SuperFact =..[Rel,SuperArg,Arg2].
covers(animal,skin).
isa(fish,animal).
isa(bird,animal).
isa(mammal,animal).
isa(shark,fish).
isa(salmon,fish).
isa(parrot,bird).
isa(penguin,bird).
speacial_organ(fish,gills).
travel(fish,swim).
birth(bird,lay_eggs).
special_organ(bird,wings).
travel(bird,fly).
birth(fish,lay_eggs).
birth(mammal,not_lay_eggs).
birth(shark,not_lay_eggs).
nature(shark,dangerous).
food(salmon,delicacy).
colour(parrot,green).
travel(penguin,walk).

这是我想从这个程序中找到答案的问题

• 鹦鹉会飞吗？
• 鹦鹉是什么颜色的？
• 鹦鹉有皮吗？
• 鲨鱼危险吗？

Answer 1

第一步：定义isa/2的自反transitive-closure（以下命名为is_a/2）

isa(fish,animal).
isa(bird,animal).
isa(mammal,animal).
isa(shark,fish).
isa(salmon,fish).
isa(parrot,bird).
isa(penguin,bird).

is_a(X, Y) :-
   closure0(isa, X, Y).

第二步：指定剩余的事实（按谓词指示符分组）。

covers(animal,skin).

special_organ(fish,gills).
special_organ(bird,wings).

travel(fish,swim).
travel(bird,fly).
travel(penguin,walk).

birth(bird,lay_eggs).
birth(fish,lay_eggs).
birth(mammal,not_lay_eggs).
birth(shark,not_lay_eggs).

nature(shark,dangerous).

food(salmon,delicacy).

colour(parrot,green).

第三步：让我们提出一些问题！

Can parrots fly?

?- is_a(parrot, X), travel(X, fly).
   X = bird
;  false.

What is the color of parrots?

?- is_a(parrot, X), colour(X, Colour).
   Colour = green, X = parrot         
;  false.

Do parrots have skin?

?- is_a(parrot, X), covers(X, skin).
   X = animal
;  false.

Are sharks dangerous?

?- is_a(shark, X), nature(X, dangerous).
   X = shark
;  false.

结果没有与给定的事实进行比较

Results are not compareing with given facts

prolog

transitive-closure