In Chinese, press and hold the key of shift+ expansion symbol to insert "{}" at the same time, as shown in the figure below.

Braces, 1593 by the French mathematician Francois Viete (Fran? Ois Viète,1540-1603) was introduced, and 18 century later, it was widely used all over the world. This symbol indicates that the purpose is expressed in a wide range through instructions and formulas. English name: brace, also called curly braces.

Application of support:

1, when it is outside the bracket, indicates the next operation outside the bracket.

2. In mathematics, it can be a set of symbols, such as: A = {x | x> 1}.

3. In mathematics, when there is only one number in braces, it can represent the decimal part of the number. For example, {5. 1} means 0. 1.