03-ilang-space / 08-cell-medium
08cell mediumverified
Summary How a body's effect on a probe's geometry depends on where the body is recorded in a medium of coupled cells: when it vanishes and at which order it appears.
# External verification: 08-cell-medium
- **Subproject:** 03-ilang-space
- **Package:** 08-cell-medium
- **Verified version:** v1
- **External round:** 1 of 2
- **Date:** 2026-10-08T11:04:58+02:00
- **Focus points:** none
---
VERDICT: correct
## Summary
The exact evolution and no-link cancellation are correct. The BCH and cumulant expansions yield the stated body-dependent fourth-order coefficient and witness-angle correction, including the signs and factors in the qubit example. The chain support-counting argument establishes the claimed \(O(\lambda^{3+r})\) bound without asserting that this order is always attained. Assumptions and small-\(\lambda\) restrictions are appropriately stated.
## Issues
None.
## Focus points
None given.