DC-EPOCH-31
DC derived enforcedRewind replay equivalence. Refolding from the settled rewind point yields state byte-identical to folding straight through from the bootstrap baseline over the same canonical chain. The bounded rewind moves only the STARTING POINT of a deterministic re-derivation, so the derived result cannot differ -- this is what makes it a performance change rather than a correctness trade.
- Source
docs/clusters/ACCUMULATOR-REFOLD-BOUND/SLICE-S1-settled-rewind-point.md (INV-AR-6)
- Introduced in
- ACCUMULATOR-REFOLD-BOUND-S1
Enforcement trace
Code
Tests 1
- refold_from_settled_point_equals_fold_from_bootstrap
Cross-references
Evidence notes
The proof folds one chain twice -- straight through, and via a promoted settled point plus rewind plus refold -- and asserts the resulting EpochAccumulator is equal; it also asserts both paths agree BEFORE any rewind so a harness that folded nothing would fail rather than pass vacuously. SUPPORTING live evidence only (never the reason for enforcement): the 2026-08-01 sustained preview run measured the UNBOUNDED pre-slice behaviour -- refold 225s at 25,838 slots from the bootstrap anchor rising to 1595s (26.6 min) at 85,690, per-slot cost climbing 0.009->0.019 s/slot, over 14 reorgs in 18h. CE-AR-6 (a live run showing refold no longer grows with uptime) is still OUTSTANDING. Enforcement rests on the named tests + ci/ci_check_accumulator_refold_bound.sh.