如何在 Prolog 中取反 [英] How to negate in Prolog

问题描述

我是 PROLOG 的新手，正处于 此页面.鉴于规则父(X，Y)和男性(X)，我试图将规则母亲(X，Y)定义为

I'm new to PROLOG and am at the very beginning of the exercises on this page. Given the rules parent(X, Y) and male(X), I'm trying to define a rule mother(X, Y) as

mother(X, Y) :-
    not(male(X)),
    parent(X, Y).

但是，在 GNU Prolog 中，我收到以下错误:

However, in GNU Prolog I get the following error:

| ?- mother(lina, julia).
uncaught exception: error(existence_error(procedure,not/1),mother/2)
| ?- 

推荐答案

\+/1 是 ISO Prolog 谓词否定".请注意，否定"在这里表示此时不可证明.

\+/1 is the ISO Prolog predicate to "negate". Note that "negate" means here not provable at that point.

您可以参考@false 的这个极好的答案以了解更多信息主题

You can refer to this excellent answer by @false for more on the subject

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