# MT, LXX and SP spine comparison: integration notes

Date: September 28, 2026. Status: reader expansion following the completed C1431 checkpoint.

The revised explanation incorporates Dean's supplied *Reversed Creation–Flood Spines: LXX Comparison and the Accepted SP Solution*. The main reader now places the comparative chapter immediately after the MT inverse-backbone explanation. Technical companion §4A supplies the common reconstruction formula and source inputs. The complete supplied study is included unchanged in the reader package, retaining its detailed comparisons, source register and corrections.

## What the comparison adds

| Tradition | Two-stage Regular / Cumulative heads, BC | Three-stage Regular / Cumulative heads, BC | Cumulative minus Regular |
|---|---|---|---:|
| MT | 12026 / 12026 | 14726 / 14726 | 0 |
| LXX | 10436 / 10936 | 13136 / 13636 | +500 |
| Accepted SP Fall | 11606 / 11416 | 14306 / 14116 | −190 |

The shared 1400→4100 tail and change of held anchor generate the same +2700 head shift in all six cases. Their different mode separations therefore persist. The common operation explains both MT convergence and the LXX/SP displacements.

The cumulative two-stage contractions are MT 1980, LXX 3960 and SP 1980. The self-reversing spans 3430/4340/8680 explain which lengths survive; the position of the surviving segment determines whether its endpoints remain stationary or move together.

The main narrative then follows the strongest cross-family connections: the SP-to-MT 300-year translation preserving 9900/9890; the LXX 910-year paired translation and separate 870 comparison; the LXX/SP arrangement around Rounded LXX Creation 5486; the return of the original SP 1700-year Flood–Conquest interval; and the LXX paired Priestly landing at the generated 386 BC point.

## Source decisions retained

- MT remains primary; LXX supplies the secondary comparison.
- The SP Fall construction is accepted: lower Rounded Creation 4411/13401 moves forward five years to Fall 4406/13396 before inversion. The Creation coordinates remain distinct.
- BJ remains derivative of the SP 1300 structure in the project's interpretation.
- LXX retains native second Cainan, the declared full-430 comparative frame and the selected 182/753 Lamech reconstruction.
- The corrected SP relation is 11606−4406=7200; 11606−4106=7500. The accepted Regular three-stage head is 14306. The factorization is 9890=23×430.
- The possible reciprocal relationship retains its proposed status; no full inverse mapping between chronologies is asserted. The inverse of the inverse remains deferred.

## Verification and edition scope

An independent calculator passed 112 exact assertions in 11 groups, checking the six spines and intermediate nodes, common stage shift, mode differences, principal cross-family intervals, exact-rational expansions and selected civil BC/AD calculations. It did not rerun the source study's claimed 164 grouped checks or independently reconstruct Report IV's underlying lifespan sums. Those remain supplied source premises. The calculation script, results and review are included in this package.

A separate reader review found the comparative chapter and technical insert consistent with the Strategy and their declared source roles. The PDFs were rendered and visually reviewed; tables, equations and the inherited map remain readable. Pagination was adjusted to keep short tables and equation lead-ins together, and a clipped inherited filename was replaced with the readable phrase “the final Covenant claim index.”

This is an expansion of the reader following C1431. The original 300-action journal, its 779-check verification and the sealed evidence archive remain unchanged. The new material has its own review; its checks are not added to the earlier count. No C1432 research action was executed.

The original four-part JSON grammar, source index and other inherited reference files in the package retain their C1431 scope. The added chapter, technical §4A, supplied study and this note document the extension. A complete selected spine does not by itself reconstruct every genealogical node.

Source study filename: `490d_LXX_Reversed_Spines_and_Accepted_SP_Solution_20260928(1).md`.

Source study SHA-256: `3083e334c2834b5b53aa2acab6aa957c1e21bd28ccb404eb91ec2158d859acdb`.

The inherited File52c and other canonical source files were not edited. The new reader versions preserve the completed checkpoint as their baseline while incorporating the requested comparison.