Nonseparable Coupling of Relational Time and Space

After time and space have each been derived independently from relational structure, whether the two structures separate as a simple direct product on the same state space is a distinct question. This study places graded Hasse incidence and same-grade locality in a common linear-algebraic framework and directly computes the longitudinal–transverse naturality defect. A direct witness establishes a nonzero defect, longitudinal branching, and slice-type change. Reversal transport and mixed-cell incidence are then used to prove a necessary-and-sufficient criterion for a fixed-fiber product. Consequently, time and space are nonseparably coupled already at the relational/combinatorial level, before introducing a metric or Lorentzian signature.