# 490d Mirror checkpoint after C287

24 September 2026. Latest completed: **C287 — The four-node529 normal form.**

Normal form S=−12K+i,F=−10K+i,R=5K+i,N=7K+i. First three exist i0–5; SP Noah completes i2–5, LXX OFF aliases i3/5. Width matrix[[17,19],[15,17]]K and both side gaps2K. Difference19K−15K=4K is a width difference, not a node edge.

## Standing context

C276: the selected cross-index alignment fixes δ=h−f=598; source transport alone does not. Absolute placement remains a separate premise. Preserve source and map roles, annual indices and ±1/4 phase ancestry. Co-located images do not identify events.

K=529; E=25/23; P=70/69. Global Mirror January AD 1; established local junction x=1, January AD 2; no civil year zero. Regular Gears Noah/Shem/Flood only. No cumulative/upstream Gears, primer reopening, canonical/graph changes or new global axis/z-law. Capture now, canonize later.

Supplement: LXX Creation 5494 BC +8464→AD 2970 versus reflected Conquest AD 1406 gives1564→1700 by25/23; Jared4534→AD3930 versus reflected Exodus1446 gives2484→2700. LXX Creation→Jared960, MT460; offsets1380/880; difference920→1000. AD3746/2300 superseded. Awareness only.

C-series reports remain distinct from original unprefixed Reports01–10 and unestablished interrupted Reports11–25. The superseded AD1905–1911 lookup remains unexecuted.

## Verification

38 mathematical/domain checks and 6 source authentication checks passed; two generated readouts replay byte identically. Author review only. File_18, File_09, C265 certificate and C127 unchanged; graph208 nodes/382 duration edges.

## Best next bounded step

C288: enumerate source-supported paths and contrast them with abstract integer combinations of K widths.

Reason for selecting it after C287: The reduced normal form invites iteration and lattice claims; testing its actual finite domains will prevent unsupported K or4K edges from being inferred.

High is sufficient unless a later dependency requires reassessment. The next step was not executed as part of C287. The authorized batch continues through C310.