语法错误：操作员期望（执行语句）

Question

我目前是Prolog的初学者，我遇到了操作错误。根据编译器，它必须对“do语句”做一些事情。任何指导都会非常感激。谢谢。

:-use_module(library(clpfd)).
:-use_module(library(lists)).

go :- 
    Mary = 1,
    John = 2,
    Jim = 3,

    Persons = [Mary, John, Jim],

    Jobs = [Gardener, Veteriarian, Dishwasher, Nurse, MathTeacher, BiologyTutor],
    domain(Jobs,1,3),

    % This means that each person holds two jobs
    global_cardinality(Jobs,[1-2,2-2,3-2]),

    %nurse went out with the veteriarian last night
    Nurse \= Veteriarian,

    %mary is friends with the biology tutor but she stayed home last night
    Mary \= BiologyTeacher, Mary \= Nurse, Mary \= Veteriarian,

    %jim likes animals but doesn't do good in math and dropped out of college
    Veteriarian = Jim, Jim \= MathTeacher, Jim \= BiologyTutor, Jim \= Nurse,

    %jim doen't know the gardener
    Gardener \= Jim, Mary = Gardener,

    %Mary and the biology teacher used to be married
    BiologyTeacher = John,

    %search
    labeling([],Jobs),

    %output
    write(Jobs),n1,
    PersonsStr = ['Mary', 'John', 'Jim'],
    JobStr = ['Gardener', 'Veteriarian', 'Dishwasher', 'Nurse', 'MathTeacher', 'BiologyTutor'],

    (   foreach(J, Jobs),
        foreach(JS, JobStr),
        param(PersonsStr, Persons) do
        ( foreach(P, Persons),
          foreach(PS, PersonsStr),
            param(J,JS) do
            P == J -> format('~w\t~w'[JS,PS]) ;
            true
        ),
            n1 
    ),

    fd_statistics.

Answer 1

您的代码使用最初来自ECLiPSe的逻辑循环结构，最近也在SICStus Prolog上找到。可以从以下网站获得SWI-Prolog的（一项明显的在制品）实施方案：

https://github.com/JanWielemaker/logical-loops

首先尝试在代码之前加载它（它是一个Prolog文件）并查看是否可以运行它。