 If we do not use parentheses to separate function and argument, how are we to disambiguate expressions that involve three or more terms, such as ‘\(PQR\)’? Recall our convention that we are to understand such officially illegal expressions by working from left to right, always putting parentheses around adjacent terms. Thus, ‘\(PQR\)’ is to be understood as \((PQ)R\). ‘\(PQRS\)’ is \(((PQ)R)S\). The expression ‘\((PQ)R\)’ is disambiguated; by our convention, it is identical to \(PQR\). The expression ‘\(P(QR)\)’ is also explicitly disambiguated; it is distinct from \(PQR\) because it is the application of \(P\) to the argument \(QR\) (which is itself the application of the function \(Q\) to the argument \(R)\).