BI publisher 对于上下文的理解哪位大侠解释下

Oracle XML Publisher Enterprise User's Guide文档中的描述如下：
inline       The context will become the single statement inside an fo:inline block. This context is used for variables.
incontext  The statement is inserted immediately after the surrounding statement. This is tt?> statements that need to follow the surrounding for-each as the first element
inblock     The statement becomes a single statement inside an fo:block (RTF paragraph). This is typically not useful for control statements (such as if and for-each) but is useful for statements that generate text, such as call-template.
inlines      The statement will affect multiple complete inline sections.

1. 变成一个单独的事务在 fo:inline block 有什么用？
2. 怎样才算一个 fo:inline block？一个 fo:inline block有什么用？
3. 这四个上下文应该怎样理解呢？


希望哪位大侠帮忙解释下~多谢大家解惑~

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