Introduction and scope

A geometrically specified causal cone and an operational transport certificate are different objects. A boundary vector in a cone, or in the closure of a set of displacements, does not by itself supply a finite protocol that transmits an unknown quantum state. The supplied description of Cheung's En08-A emphasizes this distinction, including the possibility that a generated null boundary contains no attained null event pair CheungEn08A.

The present paper supplies a connecting theorem in one explicitly declared model: \[

prescribed future-null displacement

finite local transport protocols with complete-channel
correctness, uniform geometric control, and a resource ledger.

The implication is constructed directly. No result concerning cone selection is used as a premise.

to earlier transport constructions. The supplied En05-B description already includes direction-uniform relays, reference-preserving quantum transport, and matched finite experiments. The supplied En06-B description already includes prescribed-speed finite-network transport CheungEn05B,CheungEn06B. Accordingly, En08-B is an independently proved quantitative specialization and synthesis, not a claim that either reference-preserving transport or increasing-stencil isotropy is new in general. Its particular content is a single-payload, two-site-gate model with explicit endpoint bounds, a future-directed arrival convention, a static-site memory lower bound, and complete noise accounting.

The distinction between scheduled ancestry and actual influence is also retained CheungEn05A,CheungVIIJ,CheungVIIIC. The support argument below gives an upper bound for every admissible circuit. A separately constructed SWAP circuit gives the positive transport witness.

context. Finite periodic transport structures generally have polyhedral large-scale velocity sets; Fritz gives a systematic treatment Fritz2013. Our directional permission set therefore grows with refinement. This does not contradict a fixed-stencil obstruction.

There are also constructive representation results relating unitary quantum causality to local circuit implementation ArrighiNesmeWerner. We do not invoke such a representation theorem: the local circuits used here are specified explicitly.

, rather than conclusions. Throughout, the following are externally supplied: the Euclidean spatial metric, spatial and temporal calibration, the length unit $\ell$, the speed $c$, finite-dimensional quantum channel semantics, and the permission rule. The target cone is

We approximate its prescribed null boundary. We do not infer this cone from scheduler consistency or from quantum computation.