2.2.1. assert(s) 和 report(s)

the "assert" and "report" elements are where the rules are defined in a schematron schema. both carry a "test" attribute which is an xpath expression they differ in a couple of ways:

"assert" 和 "report" 元素是在 schematron schema 中定义规则的地方。都带一个 xpath 表达式的 "test" 属性，它们在几个方面不同：

• they are the opposite one of each other: the test must be true to pass in an "assert" element and false to pass in a "report" element.
• the original purpose of assert is more for "fatal errors" and report more for things that should just be "reported", but this distinction is not relevant any longer in the latest version (1.5).

• 他们互相是对方的反面：要通过，在 "assert" 元素中 test 必须是真，而在 "report" 元素中必须是假。
• assert 起初的目的更多是用于 "致命的错误" 而 report 更多是用于那些仅仅需要 "通报" 的东西，但是这种差别在最新的版本 (1.5) 中不存在了。

there are some goodies which we will not cover in this tutorial, but the basic syntax is:

在本教程中有许多好东西是讲不到的，但是基本的语法是这样的：

  <sch:assert test="library">
    the document element should be 'library'.
  </sch:assert>

which raises an error with the corresponding message if there is no "library" element under the context node, or:

如果在上下文节点中没有 "library" 元素，它抛出一个错误和对应的信息，或者：

  <sch:report test="@*">
     the library element should not contain attributes.
  </sch:report>

which raises an error if there is any attribute under the context node.

如果在上下文节点中有任何属性，它抛出一个错误。

in both cases, the context node is set by the "rule" parent element of the report or assert node.

在两种情况中，上下文节点都是由 report 或者 assert 节点的 "rule" 父元素设置的。

2.2.2. rule(s)

schematron rule elements are roughly equivalent to xslt templates and are used to define the context under which a set of assert and report elements will be performed.

schematron rule 元素大体上和 xslt 模板相当并且被用来定义 assert 和report 元素将施加于的上下文。

an example of rule (without bells and whistles) performing the tests done in our open schema on the book element could be:

一个在我们的开放 schema 中对 book 元素执行测试的规则（没有所有的花哨的东西）的例子可能是：

   <sch:rule context="book">
    <sch:report test="@*[name() != 'id']">
     the book element should not include any attribute other than "id".
    </sch:report>
    <sch:assert test="@*[namespace-uri() = '']">
     the book element should not include any attribute other than "id" (namespace).
    </sch:assert>
    <sch:report test="@id = preceding-sibling::book/@id">
     the book id should be unique.
    </sch:report>