Major parts of documents consist of character strings, which are assembled into elements, e.g., title, clause, paragraph, etc., according to the semantics of the included character strings. The semantics and element structures are usually based on the intention of the document author.
For example, a simple document consists of the following elements
-- title --
-- author --
-- abstract --
-- heading of clause 1 --
---contents of clause 1 --------------------
| -- paragraph 1 -- |
| -- paragraph 2 -- |
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-- heading of clause 2 --
---contents of clause 2 --------------------
| -- paragraph 1 -- |
| -- paragraph 2 -- |
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