Remark: What makes the dimension finite

Without longitudinal translation invariance, the coefficients of the normal delta derivatives could themselves be distributions on $\mathcal{W}$, giving an infinite-dimensional ambiguity. Without (eq:AHclass), the scaling-degree bound also permits lower-order contacts, including a longitudinal stress proportional to $L^{-2}{\delta }_{\mathcal{W}}$. Without the reflection and charge-conjugation requirements, additional oriented tensor structures can occur. The dimension in Theorem thm:classification is not a universal dimension for every apex prescription.