Autoformat is an optional feature that your platform may (or may not) have enabled. If you are a developer, you can enable it by parameters.

Autoformat replaces some symbols from the keyboard with their better-looking counterparts. At present the replacements are:

asterisk replaced with center dot, slash replaced with fraction template, carat replaced with exponent template

The replacement is done while you type, so you never see the actual key pressed.

As you type, for example, an x followed by an asterisk, the result is an x followed by a center dot and an empty slot awaiting the rest of the multiplication problem. Similarly, the slash and carat are replaced immediately also.

Autoformat also auto-closes parentheses and alike. When you type the left fence, the right fence is automatically inserted.

These are the enclosers that have this feature:

parentheses, brackets, and braces

If you want to modify this automatic end symbol, place the cursor to the left of the symbol and write the alternate end symbol. This only works with the end symbol. If you want to replace the automatic open symbol, you must insert a new left/right pair.

See this example of an open-closed interval:

If you start with the closed interval "0 to one-half" (that is, zero comma one-half enclosed in parentheses), then place the cursor just to the left of the close parenthesis and type a closed bracket, the result is the half-closed interval "0 to but not including one-half" (that is, open paren zero comma one-half close bracket).