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Manuscript XXII-A@1 · XXII-A.tex · section · 9e4e9f66

Four warnings retained with their exact scope

The scheduler-consistency obstruction › Four warnings retained with their exact scope · lines 384–409

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The following distinctions are retained from En08-A; their predecessor arguments are not re-proved here CheungEn08A.

  1. A boundary ray of a generated, closed cone need not contain the difference of any attained operational event pair. Boundary generation or limiting approximation is not an attained null protocol.

  2. A small diamond distance from a non-signalling channel is not exact non-signalling, and hence is not exact causal containment. A positive error allowance permits a nonzero influence.

  3. A finite ordered event sample does not determine an unrestricted spacetime metric or a unique continuum realization.

  4. Chronology does not determine the full metric, including its conformal scale.

The last warning is not a denial of causal reconstruction theorems. With an entire continuum spacetime and suitable causal hypotheses, chronological information can determine conformal structure HKM,Malament. Those continuum assumptions are not furnished by a finite operational event sample. In particular, “chronology alone does not determine the metric” must not be strengthened to “chronology can never determine a conformal class.”