给定知识库的 Prolog 难题 - 不工作

Question

我知道这里有主题标题：A prolog program that reflects people sitting at a round table

但我需要一个不同的解决方案，更简单。

所以我遇到了这个问题，4 个人坐在一个正方形周围 table。

我们知道他们的名字。有人是骨科医生，有人是牙医，有人是外科医生，有人是儿科医生。

我们有一个知识库，您将在代码中看到它。

而且我们必须找到儿科医生的名字。

我的程序找到了它，但没有打印代表 table 上的座位的列表的所有四种可能组合。

table(List):-
    length(List,4),
    member(convive(argiro,_,female),List),
    member(convive(georgia,_,female),List),
    member(convive(basilis,_,male),List),
    member(convive(dimitris,_,male),List),
    left(convive(_,dentist,_),convive(argiro,_,female),List),
    oppo(convive(_,surgeon,_),convive(basilis,_,male),List),
    next(convive(georgia,_,female),convive(dimitris,_,male),List),
    left(convive(_,_,female),convive(_,orthopedist,_),List),
    member(convive(_,pediatrecian,_),List).

left(X,Y,ConLs):-append(_,[X,Y|_],ConLs).

left(X,Y,ConLs):-prefix(X,ConLs),last(ConLs,Y).

next(X,Y,ConLs):-left(X,Y,ConLs).

next(X,Y,ConLs):-append(_,[Y,X|_],ConLs).

next(X,Y,ConLs):-prefix(Y,ConLs),last(ConLs,X).

oppo(X,Y,ConLs):-next(X,Z,ConLs),next(Z,Y,ConLs),X\==Y.

在终端上我得到：

?- table(List),member(convive(Name,pediatrecian,_),List).

List = [convive(basilis, dentist, male), convive(argiro, pediatrecian, female), convive(georgia, surgeon, female), convive(dimitris, orthopedist, male)], Name = argiro ;

List = [convive(georgia, surgeon, female), convive(dimitris, orthopedist, male), convive(basilis, dentist, male), convive(argiro, pediatrecian, female)], Name = argiro ;

false.

如您所见，我得到了名字，但只有 2 个可能的列表代表每个人的座位。还应该有：

List = [convive(dimitris, orthopedist, male), convive(basilis, dentist, male), convive(argiro, pediatrecian, female), convive(georgia, surgeon, female)]

List = [convive(argiro, pediatrecian, female), convive(georgia, surgeon, female), convive(dimitris, orthopedist, male), convive(basilis, dentist, male)]

我用过台词

left(X,Y,ConLs):-prefix(X,ConLs),last(ConLs,Y).

next(X,Y,ConLs):-prefix(Y,ConLs),last(ConLs,X).

但是，他们没有做任何事情，如果我删除它们，我会得到相同的结果。

更新

table(List):-
length(List,4),
member(convive(argiro,_,female),List),
member(convive(georgia,_,female),List),
member(convive(basilis,_,male),List),
member(convive(dimitris,_,male),List),
left(convive(_,dentist,_),convive(argiro,_,female),List),
oppo(convive(_,surgeon,_),convive(basilis,_,male),List),
next(convive(georgia,_,female),convive(dimitris,_,male),List),
left(convive(_,_,female),convive(_,orthopedist,_),List),
member(convive(_,pediatrecian,_),List).

left(X,Y,ConLs):-append(_,[X,Y|_],ConLs).

left(X,Y,ConLs):-prefix(X,ConLs),last(ConLs,Y).

next(X,Y,ConLs):-left(X,Y,ConLs);left(Y,X,ConLs).

%next(X,Y,ConLs):-append(_,[Y,X|_],ConLs).

next(X,Y,ConLs):-prefix(Y,ConLs),last(ConLs,X).

%oppo(X,Y,ConLs):-next(X,Z,ConLs),next(Z,Y,ConLs),X\==Y.

oppo(X,Y,[X,_,Y,_]).

oppo(X,Y,[Y,_,X,_]).

oppo(X,Y,[_,X,_,Y]).

oppo(X,Y,[_,Y,_,X]).

因此，oppo/3 似乎在给定的列表上运行良好

?- table(List), oppo(convive(argiro,pediatrecian,female),Name,List).

List = [convive(basilis, dentist, male), convive(argiro, pediatrecian, female), convive(georgia, surgeon, female), convive(dimitris, orthopedist, male)],

Name = convive(dimitris, orthopedist, male) ;

List = [convive(georgia, surgeon, female), convive(dimitris, orthopedist, male), convive(basilis, dentist, male), convive(argiro, pediatrecian, female)],

Name = convive(dimitris, orthopedist, male) ;

false.

left/3 似乎在做我首先要解决的同样的事情，它在 argiro 为 2 且 georgia 为 3 的列表中起作用，这是一个简单的情况， 但是在上面 oppo/3 结果中可以看到的第二个列表中，argiro 是第 4 位，georgia 是第 1 位，它应该看到 georgia 再次位于 argiro 的左侧，但没有。

?- table(List), left(convive(argiro,pediatrecian,female),Name,List).

List = [convive(basilis, dentist, male), convive(argiro, pediatrecian, female), convive(georgia, surgeon, female), convive(dimitris, orthopedist, male)],

Name = convive(georgia, surgeon, female) ;

false.

现在 next/3 returns 一些非常令人不安的结果。我不知道该怎么做，我是 Prolog 的新手。有些没问题，但有些似乎将整个数组作为结果，有些说 List = Name.

前三个结果还可以，第四个和left/3一样，看不到列表中的第一个紧挨着最后一个所以它 returns 一个空数组。

这里发生了什么？

?- table(List), next(convive(argiro,pediatrecian,female),Name,List).

List = [convive(basilis, dentist, male), convive(argiro, pediatrecian, female), convive(georgia, surgeon, female), convive(dimitris, orthopedist, male)],

Name = convive(georgia, surgeon, female) ;

List = [convive(basilis, dentist, male), convive(argiro, pediatrecian, female), convive(georgia, surgeon, female), convive(dimitris, orthopedist, male)],

Name = convive(basilis, dentist, male) ;

List = [convive(georgia, surgeon, female), convive(dimitris, orthopedist, male), convive(basilis, dentist, male), convive(argiro, pediatrecian, female)],

Name = convive(basilis, dentist, male) ;

List = [convive(georgia, surgeon, female), convive(dimitris, orthopedist, male), convive(basilis, dentist, male), convive(argiro, pediatrecian, female)],

Name = [] ;

List = [convive(georgia, surgeon, female), convive(dimitris, orthopedist, male), convive(basilis, dentist, male), convive(argiro, pediatrecian, female)],

Name = [convive(georgia, surgeon, female)] ;

List = [convive(georgia, surgeon, female), convive(dimitris, orthopedist, male), convive(basilis, dentist, male), convive(argiro, pediatrecian, female)],

Name = [convive(georgia, surgeon, female), convive(dimitris, orthopedist, male)] ;

List = [convive(georgia, surgeon, female), convive(dimitris, orthopedist, male), convive(basilis, dentist, male), convive(argiro, pediatrecian, female)],

Name = [convive(georgia, surgeon, female), convive(dimitris, orthopedist, male), convive(basilis, dentist, male)] ;

List = Name,

Name = [convive(georgia, surgeon, female), convive(dimitris, orthopedist, male), convive(basilis, dentist, male), convive(argiro, pediatrecian, female)] ;

List = [convive(georgia, surgeon, female), convive(dimitris, orthopedist, male), convive(basilis, dentist, male), convive(argiro, pediatrecian, female)],

Name = [] ;

List = [convive(georgia, surgeon, female), convive(dimitris, orthopedist, male), convive(basilis, dentist, male), convive(argiro, pediatrecian, female)],

Name = [convive(georgia, surgeon, female)] ;

List = [convive(georgia, surgeon, female), convive(dimitris, orthopedist, male), convive(basilis, dentist, male), convive(argiro, pediatrecian, female)],

Name = [convive(georgia, surgeon, female), convive(dimitris, orthopedist, male)] ;

List = [convive(georgia, surgeon, female), convive(dimitris, orthopedist, male), convive(basilis, dentist, male), convive(argiro, pediatrecian, female)],

Name = [convive(georgia, surgeon, female), convive(dimitris, orthopedist, male), convive(basilis, dentist, male)] ;

List = Name,

Name = [convive(georgia, surgeon, female), convive(dimitris, orthopedist, male), convive(basilis, dentist, male), convive(argiro, pediatrecian, female)] ;

false.

更新

所以我了解到 prefix/2 适用于字符串，例如， prefix(x,[x,y,z]). returns 错误。这就是它不起作用的原因，这解释了 next/3 中的结果，但我的问题仍然没有解决。

还有其他方法可以使 left 和 next 与列表的第一部分和最后一部分一起工作吗？

Answer 1

我敢打赌罪魁祸首是 oppo 中的 \==，因为这些谓词在这里以生成方式使用。尝试摆脱它。只需手动编码四种可能性就足够了——毕竟你的列表是固定长度的，而且非常短：

oppo(X,Y,[X,_,Y,_]).
.....

next/3 如果编码为对 left/3.

的两次调用的析取，则更容易/更清晰

对于 left/3 本身，您还可以通过

从您的 ConLs 围成一个圆圈

circle_up(Ls,Circle):- head(A,Ls), append(Ls,[A],Circle).

并在对 append 的一次简单调用中使用 Circle 来完成 left/3 的定义。这假设定义

head(A,L):- L=[A|_].

给定知识库的 Prolog 难题 - 不工作

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