swi-prolog 谓词不起作用

Question

我在 swi-prolog 中有一个非常简单的程序，我在其中定义了家庭关系的所有谓词。我还定义了一些事实（基于圣经的亚伯拉罕家族）。 所以我这样定义了一个谓词“mother_in_law”：

mother_in_law(X,Y):- female(X),mother(X,Z),married(Z,Y).

还有一些事实：

female(sarah).
mother(sarah,isaac).
married(rebekah,isaac).

所以现在，当我输入程序时

?- mother_in_law(sarah,X).

它应该只给我 X=rebekah。但它给了我一些不符合我定义的条件的 X 其他值。

谁能告诉我我做错了什么？

非常感谢

我添加了整个文本部分：

father(X,Y). % Define Predicates%
mother(X,Y).
married(X,Y).
male(X).
female(X).
parent(X,Y).
diff(X,Y).
male_cousin(X,Y).
brother_in_law(X,Y).
mother_in_law(X,Y).
cousin_three(X,Y).
cousin(X,Y).
sib(X,Y).

%Define Facts%
male(terah). male(abram). male(nahor). male(haran). male(isaac).
male(lot). male(moab). male(ben_ami). male(bethuel). male(laban).
male(esau). male(jacob). male(reuben).
female(sarah). female(milcah). female(lot_daughter_1). female(lot_daughter_2).
female(rebekah). female(leah). female(dinah).
father(terah,abram). father(terah,nahor).  father(terah,haran).
father(abram,isaac).  father(haran,lot). father(nahor,bethuel).
father(bethuel,laban). father(laban,leah). father(isaac,jacob).
father(isaac,esau).
father(jacob,reuben).
mother(sarah,isaac). mother(milcah, bethuel). mother(rebekah,jacob).
mother(rebekah,esau). mother(leah,reuben).
mother(lot_daughter_1,moab). mother(lot_daughter_2,ben_ami).
married(abram,sarah). married(nahor,milcah).
married(isaac,rebekah). married(jacob,leah).
married(sarah,abram). married(milcah,nahor).
married(rebekah,isaac). married(leah,jacob).



%Define complicated predicates%
    parent(X,Y) :- father(X,Y).
    parent(X,Y) :- mother(X,Y).
    diff(X,Y) :- not(X=Y).
    sib(X,Y):- parent(Z,X), parent(Z,Y), diff(X,Y).  %define sibling %
    mother_in_law(X,Y):- female(X),mother(X,Z),married(Z,Y). %question 1%
    male_cousin(X,Y):- male(X),father(W,X),parent(Z,Y),sib(W,Z).    %question 2%
    cousin(X,Y):- parent(Z,X), parent(W,Y), sib(W,Z).       %question 3%
    cousin_three(X,Y):- parent(Z,X),parent(G,Z),parent(H,Y),parent(K,H),cousin(G,K).
    brother_in_law(X,Y):- male(X),married(X,Z),sib(Y,Z). %question 5-X is married to Y's sibling%
    brother_in_law(X,Y):- male(X),sib(X,Z),married(Y,Z).  %X's sibling is married to Y%
    brother_in_law(X,Y):- male(X),married(X,W),married(Y,Z),sib(W,Z).  % Y is married to the sibling of X's spouse%

Answer 1

将以下内容添加到您的事实中。然后就可以了。

married(isaac,rebekah).

更好的方法可能是让已婚关系本身处理已婚（A，B）与已婚（B，A）相同的事实

Answer 2

您的解决方案的问题是由于以下事实

mother_in_law(X,Y).

声明任何人都是其他人的岳母。

放下

father(X,Y). % Define Predicates%
mother(X,Y).
married(X,Y).
male(X).
female(X).
parent(X,Y).
diff(X,Y).
male_cousin(X,Y).
brother_in_law(X,Y).
mother_in_law(X,Y).
cousin_three(X,Y).
cousin(X,Y).
sib(X,Y).