Computer-assisted obstruction

QA-BUCK-CAN-015

Canonical-section obstruction

Exact statement

All 27 labelled eight-half patterns fail the mod-three singleton-vector receipt in the canonical BKL section.

StatusExact but section-relative
External reviewNo documented external or specialist review of this Quotient Arsenal result is recorded.

Context

Finite quotient words do not lift one factor at a time independently. Local affine lift fibres must be transported through the ordered product; the target defect then lives in a product-image cokernel that is invariant under quotient Hurwitz moves.

Proof or evidence

All canonical patterns are enumerated and rejected in the pinned finite model.

Verification notes

The colored-crossing, diagonal-selection, and three-strand shadow proofs were reconstructed. An independent implementation enumerated all 2,925 three-support multisets and 256 positive shadow words. The later winding closures remain at L3 because their archived replay dependency is still unavailable.

Limitations

  • Arbitrary winding changes the lift fibre, so the result is not a global nonexistence theorem.

Open work

Analyze the complete winding fibre rather than another fixed section.