Remark: Exact normalization is stronger than a classical limit

If one imposed only equality of the ${\hslash }^0$-coefficient, positive-$\hslash$ changes would not be excluded by that weaker requirement. Theorem thm:unique uses either the $\hslash$-independent degree-one sheet, or the full coefficientwise equality explicitly stated above. It is not uniqueness among all possible interacting normalizations.