| 1. | If a set contains no elements we shall designate it by Ф and define it as the empty or null set .
如果一个集合不包含元素，我们就把它记为，且定义它为空集或零集。 |
| 2. | A string consisting of all of the element s styles
包含元素的所有样式的字符串。 |
| 3. | Object is the key for the containing element ; otherwise ,
对象是包含元素的键，则为 |
| 4. | The root node of the result tree has an element child
结果树的根节点包含元素子级。 |
| 5. | Or the constraint can be moved to the contained element
也可以将此约束移动到被包含元素： |
| 6. | Value along with the rest of the containing
包含元素的其余部分。 |
| 7. | Object to be the key for the containing element when implementing the
对象定义为包含元素的键。 |
| 8. | Attribute values can contain only text , not element markup
属性值只能包含文本，不能包含元素标记。 |
| 9. | Has a signature containing element type
有一个包含元素类型 |
| 10. | Of nodes in an xml document in a convenient and compact form
请注意，为简单起见，该文档只包含元素。 |
