# 490d Mirror checkpoint after C293

24 September 2026. Latest completed: **C293 — The13K arrangement and fixed8K reflection.**

J8K(y)=4232−y requires5K−i and7K−i; common-row partners are5K+i and7K+i, leaving2i residual. At i0 the inner generated/source pair1587↔2645 exists but Noah3703 is missing. Complete SP rows i2–5 have residuals4/6/8/10, with the same phase residual.

## 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 AD3746/2300 superseded.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 The superseded AD1905–1911 lookup remains unexecuted.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

26 mathematical/domain checks and 8 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

C294: release the common annual offset, retaining the fixed13K bridge and8K reflection, and test the full two cumulative fields against the existing regular register.

Reason for selecting it after C293: The common-offset family fails, but the full fields contain additional source indices. A bounded source search can distinguish a true closure boundary from a restriction caused by the chosen pairing.

High is sufficient unless a later dependency requires reassessment. The next step was not executed as part of C293. The authorized batch continues through C310.