如何在 Prolog 中使用 DCG 生成长度为 n-1 的所有二进制字符串的语言

Question

z(1) --> [].
z(N) --> [0] , z(Nm), {N is Nm+1}.
z(N) --> [1] , z(Nm), {N is Nm+1}.

这就是我目前所拥有的。我要生成

[0,0]
[0,1]
[1,0]
[1,1]

但在 [0, 0]

之后进入无限循环

查询时

?- z(3, X, []).

Answer 1

如果你总是调用N为整数的谓词，你可以尝试：

z(1) --> [].
z(N) --> [0] , {N>1, Nm is N-1}, z(Nm).
z(N) --> [1] , {N>1, Nm is N-1}, z(Nm).

结果：

?- z(3, X, []).
X = [0, 0] ;
X = [0, 1] ;
X = [1, 0] ;
X = [1, 1] ;
false.

How to generate the language of all binary strings of length n-1 using a DCG in Prolog