It usually means a pause after a hint or a hint below or a summary above.

In mathematical language: ① indicates the ratio relationship between them, such as 1: 2, x:y, f (x): g (y); ② Represents the two-point product of two dyadic vectors, such as AB: CD = (A C) (B D).

Function:

1. Used as a salutation, it means to mention the following. Comrades, let's have a meeting now. It often appears in letters and official documents. Some people often ignore this colon after the address form, which is easy to write as a comma.

Used after the words "say", "think", "yes", "prove", "announce", "for example" and "as follows", it means the following.

3. Used after the conclusion words, it indicates that the following arguments are caused.

For example:

There are four gates in the Forbidden City in Beijing: Wumen Gate, Shenwu Gate, Donghuamen Gate and Xihuamen Gate.

4. Used after the words that need to be explained, it means to lead to an explanation or explanation. For example: "Title: Integrity." "Motto: not the best, but the closest."

5. Summarize the above contents with the previous general discussion.

Example 1: "I can't figure it out, nine cows can't be pulled back; After thinking about it, don't let anyone say it, go straight ahead: he is such a straight temper. "

Semicolon is a punctuation mark between comma and period, which is mainly used to separate two clauses with certain relationship (juxtaposition, turning, undertaking, cause and effect, etc.). )-Clauses can belong to a single repetitive sentence, or they can be the first-level clauses of multiple complex sentences, or they can be the juxtaposed parts of big sentences. In addition, semicolons can also be used to separate parallel phrases that appear as enumerations, or different interpretations of the same meaning in dictionaries. See the text for details and examples. In addition, "semicolon" can also mean "branch"

In a repeated sentence, when the clause does not contain commas, it can be separated by commas or semicolons, and when it does, it can be separated by semicolons. Note that semicolons are punctuation marks in sentences, that is, semicolons cannot be used for coordinate relations in sentence groups.

Example 1

1. Mineral resources, water, forests, mountains, grasslands, wasteland, beaches and other natural resources are all owned by the state, that is, by the whole people; Except for forests and mountains, grasslands, wasteland and beaches that are collectively owned by the law. (Constitution of People's Republic of China (PRC))

2. In fact, many occupations do not require people to have high talent in language and logical mathematics; On the contrary, many jobs often require people to have strong spatial imagination and athletic ability. (Zheng, Intelligence of Modern People)

Semicolons are used to separate the first-level clauses of multiple complex sentences, regardless of the logical relationship of several clauses in this level clause. First of all, we should examine the situation of parallel relationship.

Example 1

1. Some learn flue-cured tobacco and make their own exquisite cigarettes and cigars; Some learn to process vegetables, and the ketchup can be eaten until winter; Some learn to pickle and hoard vegetables, so that autumn vegetables and spring vegetables can be linked together. (Wu Boxiao's Notes on Gardens)

2. For example, the spoken language of the people at that time was often used in character dialogues, which made us feel that we heard their voices; Another example is action description, which uses only a few words to write the image vividly on paper. (Mao Dun's Talking about Man and Structure)

The coordinate clauses separated by colons, dashes, brackets and quotation marks in large sentences are relatively independent, and semicolons can be used in the middle as needed.

illustrate

1. They are thinking: When mountain torrents come, which streams are difficult to pass, so stone bridges and slab bridges will be set up; Too far away from the river, a well will be dug next to the scattered cottages; Which wells are close to the road, and the manhole cover is added to the well. (Wei Wei's "Parting Feelings")

2. There are many stresses in hunting: to hunt pheasants and rabbits during the day is called playing slope; Wild boar, fox, badger, bear and wolf all want to fight at night. This is called hunting. (Orion in Wu Boxiao)

If the sub-item is a clause, you can naturally use a semicolon. In a simple sentence, coordinate phrases headed by colons are used for enumeration, or they can be separated by semicolons to highlight the nature of enumeration.

illustrate

1. distinguished professor's job responsibilities are: teaching the core courses of this subject; Presided over the research of major national scientific research projects; Leading the construction of academic echelon in this discipline; Lead the discipline to catch up with or maintain the international advanced level in its frontier fields. (Guangming Daily 1998.8.5)

2. Words can be roughly divided into three categories: (1) poems; (2) alto; (3) Long tune. (Wang Li's "Poetic Metrics")