LESR FINAL STRESS CHECKPOINT — 09V_EXACT_CORE_TIER
Date: 2026-09-23
Target: tail Aref hard-core acceleration

NEW RESEARCH PROOF TIER:
EXACT_ERODED_CORE_SUPPORT

Semantics:
- For a parameter box, let K_c be the center Reuleaux body.
- Let delta be the same Hausdorff motion bound already used by the historical finite kernel.
- Convex Hausdorff control implies K_c ⊖ delta B is contained in every actual body in the box.
- For Reuleaux bodies represented as intersections of equal disks,
  K_c ⊖ delta B = intersection of the same center disks with radius reduced from 1 to 1-delta.
- The historical kernel inscribed finite polygons in this eroded core.
- The new tier evaluates the eroded core itself by its exact finite support-arc/vertex pieces, then computes the convex-hull support envelope with the fixed disk.
- Therefore it is a stronger lower witness under the same declared research arithmetic semantics, not a heuristic replacement.

CANONICAL REPLAY:
- At erosion radius 1, generated B3/B5 support pieces reproduce the original canonical Reuleaux support pieces to ~1e-16.

CROSS-CHECK AGAINST OLD K1024:
- Tested all 337 current hard frontier boxes.
- exact-core lower - K1024 lower:
  minimum = 1.946400625341127e-06
  maximum = 3.123937379001518e-06
- 0 regressions.

INTERIOR FALSIFICATION:
- 640 random actual placements sampled inside existing hard frontier boxes.
- For every sample: actual exact-envelope area >= exact-core lower - 1e-9.
- Minimum observed actual-minus-lower margin = 1.441627815130797e-04.
- 0 violations.

PERFORMANCE:
- exact-core support lower ~0.32 ms/box on benchmark.
- historical K1024 lower ~0.43 ms/box.

IMMEDIATE FRONTIER EFFECT:
- 24 / 337 unresolved frontier boxes close immediately before any new subdivision.

CAMPAIGN:
- New delegated persistent state directory:
  LESR_09V_Tail_Aref_ExactCore_States
- Source prefix:
  LESR_09V_Tail_Aref_Lookahead_States
- Existing closed prefix evidence remains frozen.
- Split scheduler remains deterministic K64/RING256 lookahead.
- Leaf proof tier is now exact eroded-core support (plus NOT-F3).

AUTHORITY:
- RESEARCH proof tier.
- Publication-level directed-rounding / independent-backend audit remains open.
- Tail not yet globally closed.
- Root6217 positive rotation not yet globally closed.