Parenthesized expression
Parentheses can be used to enforce a particular order of evaluation in expressions that contain multiple operators.
For example, the expression (2 + 4) * 5 evaluates
to thirty, because the parenthesized expression (2 + 4) is
evaluated first, and its result is multiplied by five. Without parentheses,
the expression 2 + 4 * 5 evaluates to twenty-two,
because the multiplication operator has higher precedence than the
addition operator.
Empty parentheses denote an empty sequence.