Fixed-endpoint integrability at the R-322 terminal step #
The final carrier collapse is a generalized primitive kernel whose edge
family is the current heterogeneous edge state. Reachability supplies
measurability of every such edge, while the quantitative edge certificate
supplies its class-E membership and off-diagonal inverse-square bound.
The scaled off-diagonal primitive-integrability theorem can therefore be
applied directly at each fixed pair of endpoints.
In particular, no exceptional endpoint is selected from a joint Fubini statement: the result below holds pointwise in both endpoints.
Every closed primitive summand in a reachable terminal carrier has an absolutely integrable internal section, pointwise in both fixed endpoints.
The exact fixed-endpoint package consumed by the terminal-collapse identity. The nonzero endpoint assumption belongs to the subsequent Proposition 4.1 estimate; integrability itself also holds on the diagonal.