Internal reconstruction is not characteristic composition

This is the locally proved algebraic interface in CheungXIVJ (prop:descent). It constructs no distributional product.

For example, $q{\delta }^{\prime }(q)=-\delta (q)$. Thus two separately nonzero presentation terms can reconstruct zero. The supplied XIV-J null-presentation check consequently qualifies presentation-degree bookkeeping without invalidating XIV-I's internal reconstruction or frequency estimates CheungXIVJ (lem:null). An intrinsic joint-symbol claim would require the relevant descent and composition theorems.