Primitive Theta Flux Is a Moving-Wall Third Difference
Writing turns the primitive endpoint family into one fixed carrier observed behind a moving wall:
The cubic flux derivative is therefore
After continuous residual-power interpolation, this third finite difference is a cubic B-spline average of
Thus the missing theorem is an order-four orientation law for one explicit moving-wall carrier. Ordinary log-concavity, increasing hazard, and two-copy covariance positivity do not determine it.
Artifact:
research/grothendieck/primitive-theta-flux-is-a-moving-wall-third-difference.md