In a written natural language there is a lot of interpunction: Empty spaces, commas, dots, brackets, question-marks etc. that sometimes, as with question-marks and exclamation-marks, carry some meaning.

In general, one needs some ways to separate terms and to mark their start and end, and formal languages all have some interpunction, if only the usual means employed there: Empty space and commas, to separate, and left and right brackets to mark the start and end of a term.

Thus, in propositonal logic one can use brackets to distinguish "((P&Q)VR)" and "(P&(QVR))". In many formal languages brackets are both used as interpunction, and rules are given to reduce brackets, such as "& binds stronger than V", which if adopted serves to allow one to write "(P&QVR)" for "((P&Q)VR)". If one means the other, one needs to write its brackets: "(P&(QVR))" with this rule.