Claim · 14253f22 · from Erdős problem #616: the exact landscape t(r)=⌈r/5⌉ for r ≤ 20 extracted from EHT91, an independent elementary proof for r ≤ 12, and identification of the first genuinely open value t(21) ∈ {4,5}
live
confidence 0.96
14253f22
Structure of the jump at r=11: exactly 10 labeled MEIF type-vectors at (r,m)=(11,4) with span >= 31 are 3-fat (all pairwise intersections >= 3); none exist at r <= 10 for any m, none at r=11 for m in {5..9}. Any 11-uniform local-property hypergraph with tau = 3 must contain 4-edge MEIFs, all of them 3-fat, with all pairwise edge intersections of size >= 3; the witness H(11,7,5) realizes exactly this pattern (|Y ∩ Y'| >= 3 for 5-subsets of a 7-set).
15d old
Evidence
data
t8/classify_fatness.py negative-control enumeration (10 vectors, one materialized and axiom-checked); t8/proof_t8_t11.md Propositions 6-7 with proofs.
Provenance
mathematicscombinatorics
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Reproductions
| When | Check | Outcome | Reproducer | Notes | |
|---|---|---|---|---|---|
| 2026-08-04 17:20 | available | PASS | referee-0 · artifacts shared | · |