RDF 容器和集合之间的区别? [英] Difference between RDF Containers and Collections?

问题描述

我读过一本书

容器和集合之间的区别在于容器始终是打开的(即，可以通过额外的 RDF 语句添加新成员)而集合可能是关闭的.

The difference between containers and collections lies in the fact that containers are always open (i.e., new members may be added through additional RDF statements) and collections may be closed.

我不太清楚这种区别.它表示不能将新成员添加到集合中.如果我将最后一个 rdf:rest 属性的值从 rdf:nil 更改为 _:xyz 并添加

I don't understand this difference clearly. It says that no new members can be added to a collection. What if I change the value of the last rdf:rest property from rdf:nil to _:xyz and add

_:xyz rdf:first <ex:aaa> .
_:xyz rdf:rest rdf:nil .

因此我可以添加一个新成员 _:xyz.为什么又说收藏品已关闭?

I am thus able to add a new member _:xyz. Why does it then say that collections are closed?

推荐答案

关键区别在于，在 Container 中，您可以简单地继续添加新项目，只需断言新的 RDF 三元组.在集合中，您首先必须删除一个语句，然后才能添加新项目.

The key difference is that in a Container, you can simply continue to add new items, by only asserting new RDF triples. In a Collection, you first have to remove a statement before you can add new items.

这是一个重要的区别，特别是对于 RDF 推理.这很重要，因为 RDF 推理采用了开放世界假设 (OWA)，简而言之，它指出，仅仅因为某个事实不为人所知，这并不意味着我们可以假设该事实是不真实的.

This is an important difference in particular for RDF reasoning. It's important because RDF reasoning employs an Open World Assumption (OWA), which, put simply, states that just because a certain fact is not known, that does not mean we can assume that fact to be untrue.

如果你把这个原则应用到一个容器上，并且你问容器有多少物品"这个问题，答案肯定是我不知道"，因为没有办法确定有多少未知 项可能在容器中.但是，如果我们有一个集合，我们有一个显式标记最后一个项目，所以我们可以肯定地说这个集合包含多少项目 - 不可能有未知的附加项目.

If you apply this principle to a container, and you ask the question "how many items does the container have", the answer must always be "I don't know", simply because there is no way to determine how many unknown items might be in the container. However, if we have a collection, we have an explicit marker for the last item, so we can with certainty say how many items the collection contains - there can be no unknown additional items.

这篇关于RDF 容器和集合之间的区别?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！