# C278 author review

Question: Do the forward and reverse two-year shifts close on the retained SP register?

Conclusion: The598/600/602 comparisons have counts4/6/4. Two-year shifts form two finite parity chains and are inverse only on restricted domains.

The exact results were inspected against the source register and independently expressed domain identities in the checker. The second run verifies deterministic reproduction, not independent scientific review. No new agent review is claimed.

Limits:

- Ambient affine identities do not establish a global action on a finite event register.
- Numerical fixed points do not fill missing source roles.
- 598/602 cross-Gear comparisons do not change the600-year same-Gear lifespan.

The report and checkpoint are authored interpretations. The verifier authenticates the supplied inputs and calculations; it does not prove historical intentionality. Original dependencies and all standing controls remain unchanged.