Question

我们刚开始在我的一个编程课程中学习Prolog。我收到了一些错误，我不确定是什么导致了它们。这是作业，所以我不期待任何书面答案，但任何提示都将不胜感激。

这是我的代码：

/* Database for family. It consists of facts and rules. */

/* Facts */
male(mark).

/* Question 1.1 */
male(tom).
male(eric).
male(josh). 
male(austin).

/* Question 1.1 */      
female(jen).
female(beth).
female(lisa).
female(alice).
female(alex).

father_of(mark, beth). /* mark is the father of beth */

/* Question 1.1
father_of(josh, eric).
father_of(eric, mark).
father_of(eric, jen).
father_of(austin, alice).

mother_of(jen, tom). /* jen is the mother of tom */

/* Question 1.1
mother_of(lisa, eric).
mother_of(alex, alice).
mother_of(alice, jen).
mother_of(alice, mark).

/* Rules */

is_male(X) :-
male(X);
father_of(X, _).

/* Question 1.2 */
is_female(X) :-
    female(X);
    mother_of(X, _).

/* Question 1.3 */
grandfather_of(X, Z) :-
  father_of(X, Y), 
  (mother_of(Y, Z); father_of(Y, Z)).


grandmother_of(X, Z) :- 
    mother_of(X, Y), 
    (mother_of(Y, Z); father_of(Y, Z)).

我收到的错误： /tmp/gplc0GI9tg.o：在函数`Lpred7_1＆＃39;：

（。text + 0x2d1）：对predicate(mother_of/2)' /tmp/gplc0GI9tg.o: In function谓词的未定义引用（grandfather_of / 2）＆＃39;：

（。text + 0x35d）：对predicate(mother_of/2)' /tmp/gplc0GI9tg.o: In function谓词的未定义引用（grandmother_of / 2）＆＃39;：

（。text + 0x3a8）：对predicate(mother_of/2)' /tmp/gplc0GI9tg.o: In function谓词的未定义引用（grandmother_of / 2）＆＃39;：

（。text + 0x3ed）：对谓词（mother_of / 2）＆＃39;的未定义引用 collect2：错误：ld返回1退出状态编译失败

Answer 1

查看您的代码段，以下行是虚假的：

/* Question 1.1
father_of(josh, eric).

同样的事情，不久之后：

/* Question 1.1
mother_of(lisa, eric).

我认为你在写下以下事实之前想结束各自的评论。

最佳做法：只要足够的话，就可以使用行尾注释（以%开头）。

Prolog编译错误＆＃34;对谓词的未定义引用＆＃34;

1 个答案: