Group constructions cannot refute the Set Cover Conjecture, including tensor powers

For k≥2 and m≥1, a Strassen combinatorial degeneration of a finite group tensor onto the mth tensor power of the balanced tripartitioning tensor T_k requires |G|≥binom(3k,⌊3k/2⌋)^m>τ_k^m, where τ_k=8^k binom(3k,k)binom(2k,k)/27^k. For single-copy group restrictions, |G|≥2^{3k−1}; the partition products factor through commuting elements even when G is nonabelian.

Sources for this record

What was already known

Pratt’s 2023 preprint, published at STOC 2024, relates the Set Cover Conjecture to the asymptotic rank of balanced tripartitioning tensors and gives a group construction with size 8^k/2. This project proves its optimality among group restrictions and a barrier for combinatorial degenerations, including tensor powers.

AI involvement AI-led

Eyal Merhavi chose the problem and directed the research. The project explicitly credits Anthropic Claude agents with the theorem statements, informal proofs and Lean proofs, including the general-group rigidity and tensor-power barrier. Human direction is documented; task-only autonomy is not.

Importance Notable

Closes a specified group-construction route to beating the tensor threshold in Pratt’s Set Cover reduction, including joint constructions on tensor powers. The unrestricted tensor-rank problem remains open.

Limitations

These are bounds on the size of the ambient group and on bounds inherited from this construction method. They do not lower-bound the unrestricted rank or border rank of T_k and do not prove the Set Cover Conjecture. Pratt’s reduction and the passage from an embedding to a rank bound are cited external inputs. Novelty searches were not exhaustive, and no independent human mathematical review is reported.

Technical verification Formal (Lean)

The exact-commit Palomar preflight job completed its Comparator and challenge-provenance audit on 28 October. The independent statement and proved solution cover the group-size inequalities, commuting-factor rigidity and tensor-power quantifiers; the configuration permits only propext, Classical.choice and Quot.sound. This documents machine checking of these statements. It does not check the cited external Set Cover reduction.

Formal checking

The exact-commit Palomar preflight job completed its Comparator and challenge-provenance audit on 28 October. The independent statement and proved solution cover the group-size inequalities, commuting-factor rigidity and tensor-power quantifiers; the configuration permits only propext, Classical.choice and Quot.sound. This documents machine checking of these statements. It does not check the cited external Set Cover reduction.

Checker
Palomar standard mechanical verifier: Lean and Comparator
Scope
For k≥2 and m≥1, a Strassen combinatorial degeneration of a finite group tensor onto the mth tensor power of the balanced tripartitioning tensor T_k requires |G|≥binom(3k,⌊3k/2⌋)^m>τ_k^m, where τ_k=8^k binom(3k,k)binom(2k,k)/27^k. For single-copy group restrictions, |G|≥2^{3k−1}; the partition products factor through commuting elements even when G is nonabelian.
Basis
Reported by the linked checker
Check date
2026-10-28
Evidence source

Checking a formal statement does not establish that it matches the original problem.

Human understanding Few

Few is the default when evidence for a higher level is insufficient. No named human explanation of the central rigidity and tensor-power arguments is documented. Agent cross-checks and a generated proof narrative do not establish human understanding.

Correction and publication history

2026-10-29 · publication

Newly reviewed AI-led general-group rigidity and tensor-power barrier with exact-source machine-check evidence.

Read this published revision