# 490d Mirror checkpoint after C331

24 September2026. **C331 complete; C332 unexecuted.** 2 steps remain in the current authorization. Read this checkpoint and report first; frozen predecessor records retain earlier findings. Current decisions override stale archive instructions. Do not repeat completed research.

## Current result

AllfourcompleteC287SPpaths support1058=950+108. Primary paths are460+490+108; companion paths withactualMTNoah are459+491+108. AbsentMTcompanion3245/3247 isnotcreated.

The four complete SP paths already admitted in C287 all support **2K=1058=950+108** when their existing matched Noah-death endpoint is inserted. The more detailed490 partition is confined to the two primary paths; the two companion paths give491 with the actual MT Noah source record.

Use N for SP Noah birth, M for same-Gear restored MT Noah birth, D for the matched SP Noah death, and R for C287's next-Gear MT Flood boundary. Coordinates below retain the established reflected-coordinate comparison convention and their underlying BC source-station labels.

| C287 i / SP station | N→M→D→R | Adjacent intervals | R identity |
|---|---|---|---|
| 2 / G1 companion | 3705→3246→2755→2647 | 459+491+108 | MT G2 Flood close |
| 3 / G1 primary | 3706→3246→2756→2648 | 460+490+108 | MT G2 Flood start |
| 4 / G2 companion | 3707→3248→2757→2649 | 459+491+108 | MT G3 Flood close |
| 5 / G2 primary | 3708→3248→2758→2650 | 460+490+108 | MT G3 Flood start |

In every row, N−D=950 and D−R=108. The true MT Noah→R interval is598 in the primary rows and599 in the companion rows. Primary gives598=490+108; companion gives599=491+108. Both total1058 because the first context leg changes inversely,460 versus459.

The hypothetical MT Noah births required to keep460/490 on the companion rows are3245 and3247. Neither exists in the held MT register. C281's established coverage boundary therefore remains intact: an SP person-companion coordinate cannot be assigned an MT Noah identity. MT Flood close is a separately admitted event boundary, not an MT person companion.

All inserted M and D endpoints are selected by tradition, event role, Gear and source context before their differences are evaluated. D retains primary inclusive/harmonic or ordinary-companion qualification as applicable. No death endpoint or intermediate anchor was fitted to108 or490. The first two incomplete C287 rows remain incomplete. Its co-located LXX Noah labels are retained without asserting an additional LXX death-path study.

All64 independent four-vertex phase assignments were tested; eight preserve the three annual legs, exactly the two equal-output-phase choices per path. The original2K/17K edges and cumulative ancestry remain unchanged. Equal actual phases do not make these separate source pathways independent witnesses.

The targeted locator found the adjacent-Gear1058 relation and its598+460 primary dissection already explicit in C10, then retained in C287. It did not find the named950/108 dissection in the inspected sources. Thus this is a newly explicit source-qualified partition of an established2K edge, not a newly discovered2K relation or archive-wide novelty claim.


## Retained context

C323 remains the completed predecessor synthesis. Retain the six-coordinate OFF600 rectangle family and three nativeON/restored-MT primary counterparts; the full same-Gear Noah-bound SP→MT biography translates by460, with source textual502 a distinct binding. C314 reversal requires i+j=10 and opposite cumulative phases. C313/C315 same-ancestry500/600 failures remain. C287 full domain is i2…5. The paired+2 choices produce its all-K form, but the00 control also retains two17K paths. The optional combined support criteria alone isolate i=j5. No source-prescribed selector has been established. Corrected LXX8464 supplement remains awareness only (1564→1700;2484→2700;920→1000); AD3746/2300 is superseded. Earlier reports, original unprefixed reports and Engine series remain distinct.

Mirror/529 focus: K=529, E=25/23, P=70/69. Global paired Mirror January AD1; local junction January AD2; no civil year zero. Regular Gears are Noah/Shem/Flood only. SP minus-one person companions remain local to SP Noah/Shem; Flood close is a separate boundary. No upstream/cumulative Gear, new endpoint or phase, fitted anchor, global axis, primer reopening, canonical or graph edit. Capture now; canonize later. Source identity, context, modal binding, generated coordinates and phase ancestry stay distinct.

## Verification

34 main checks and 16 frozen-input/predecessor authentication checks passed. A second main replay produced byte-identical DATA/RESULTS. Independent review and its scope are recorded in the evidence. All frozen originals and standing controls remain unchanged. Verification counts are not independent-witness counts.

## Best next bounded step

C332: Test the new950/108 and490 conditions against C319’s already frozen00/02/20/22 control menu. Do they force both+2 choices, or does a source-admitted alternative retain the death partition?

The new partition is exact. Its value for selecting the529 construction depends on whether it supplies an additional constraint or simply restates one existing2K edge; the previous finite control menu can decide this without a new search.

Continue within the authorized batch, reassessing after the next completed result.