C240 — The 1656 tail and the MT antediluvian span have distinct endpoints

23 September 2026 · Step 35 of 60, continuing C205.

C239’s middle tail equals the retained MT Creation-to-Flood span 4114−2458=1656. However, its own endpoints are reflected Conquest and reflected MT Noah birth.

The numerical match is exact in the stated source profiles. It does not establish endpoint identity, a new Gear on Creation, or a common expansion map between the two intervals. The 1656 tail is already determined by 7475−5819. Its potential thematic interest can be retained without counting it as an independent 529-family derivation. The original full-430 MT source state is explicitly distinguished from the minimum 3899 state in File_18.

Evidence and scope

K=529 and r=25/23. BC base B means (B+1)t/Bn BC; reflected AD base A means AD At/(A+1)n. Their civil span is B+A in both seasonal components, with no year zero. Signed paired centers are −B and +A; the center model uses components ±1/4 and restores this separation after dilation. An interval center is geometry, not an event or a proposed universal Mirror axis.

Regular Gears are restricted to Noah/Shem/Flood. Creation and Conquest retain fixed source-field members; no fourth Gear is admitted. Generated coordinates, source-field membership and stored graph incidence are distinct. File_18/File_09 and the frozen C127 graph are unchanged. Earlier N01/N03 qualifications, the missing Shem join, closed primers and unestablished original Reports 11–25 remain unchanged. This packet selectively uses prior evidence; it does not rerun completed campaigns. Assertions and alternative placements are not independent historical witness counts.

4 step-specific checks and 19 frozen-input checks passed. Exact inputs, results and predecessor hashes are in the accompanying JSON records; calculation code is in the evidence archive. Source dependencies are identified in the body and frozen in sources/.