Methods: Using sogou and other input methods, enter the selected 5, cross-check 5 (the symbol that may come out of the corner), and select 5. .....

If not, there is a special character in the input menu. Look for it.

The contents can't be typed, and they must be in software such as geometric drawing board. Complement can be entered directly as I started. C, if the separator is |, find a key on the right side of the keyboard with | above and \ below \ and then shift+ ... you know.

As long as the names of many symbols are accurate, they should be directly input into the input method.