random - Swi-Prolog：未定义的程序：random_permutation/2

Question

为什么这个谓词random_permutation不起作用？

http://www.swi-prolog.org/pldoc/doc_for?object=random_permutation/2

?- use_module(library(random)).
%  library(pairs) compiled into pairs 0.00 sec, 8,880 bytes
% library(random) compiled into random 0.04 sec, 333,032 bytes
true.

?- L=[1,2,3,4,5], random_permutation(L,P).
ERROR: toplevel: Undefined procedure: random_permutation/2 (DWIM could not correct goal)

我怎样才能让它工作？

Answer 1

请仔细检查您使用的版本。我使用的是 5.10.5，库的大小似乎不匹配。

3 ?- use_module(library(random)).
%  library(pairs) compiled into pairs 0.00 sec, 4,568 bytes
% library(random) compiled into random 0.03 sec, 46,624 bytes
true.

4 ?- L=[1,2,3,4,5], random_permutation(L,K).
L = [1, 2, 3, 4, 5],
K = [1, 3, 2, 4, 5].