Peter Suber, "Propositional Logic Terms and Symbols"

To indicate that a compound is to be taken as a whole or single statement, we put it in parentheses. For example, p q is a compound. Its negation is (p q). When the negation sign is outside the parentheses, it affects the entire compound, not just the first component, p. Its conjunction with the compound, q r, would be expressed, (p q)·(q r). If we wanted to say that the whole latter statement was false, we would write, [(p q)·(q r)].