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Distinct odd covering system

Does there exist a distinct covering system all of whose moduli are odd?

Why this problem

A finite witness would settle the existence direction, but structural lower bounds make it a later discovery-lane target.

Verification contract

An explicit finite covering system can be checked over one least-common-multiple period.

Tracking
Difficulty
7/10
Attempts
1
Last attempt
2026-07-21 04:53 UTC
Source status
verifiable
External validation
none
Techniques and harnesses
exact covercovering congruencesSATLCM-period verification
Resumable campaign memory

Research map

1 epochs · 0 promising · 0 blocked · 4 ruled out
Next session checkpoint

Decide whether the four-prime weight-function theorem can be rigorously repaired.

First action: Test and then prove or falsify |C_d intersection W|/|W| <= product over support of p^(-b)(p-1)/(p-2), beginning with exact exhaustive controls for primes {3,5,7} and exponents <=3.

Stop or redirect when: Stop at the first exact counterexample; otherwise stop after a complete proof and novelty audit determine whether the resulting theorem is valid and new.

Open leads
  • Repair or refute the four-prime weight-region argument using normalized intersection ratios.
    Exhaust tower assignments at primes 3,5,7 and exponents at most 3 using exact Fractions.
  • Machine-check published condensed covering trees.
    Define a JSON split-tree schema and encode the published t_15 <= 4 construction.
  • Seek a square-free near-cover with one prime repeated exactly twice.
    After tree tooling exists, encode the published tau_7 <= 6 tree and test a bounded replacement grammar.
Strategy registry
  • counterexample-guided inductive synthesis
    Use a verified split-tree grammar to replace repeated leaves while retaining counterexample CRT fibres.
  • symbolic and congruence family discovery
    Replace absolute weight-region cardinalities by normalized CRT fibre ratios and sum geometric prime-power towers.
  • isolated adversarial reconstruction
    Compare exact source hypotheses with claimed encodings, isolate the smallest exact discrepancy, and validate witness tooling using independent algorithms.
    Reopen only if: For the few-prime route, establish a corrected normalized-region lemma handling arbitrary tower overlaps and edge cases; for the Lean route, replace both custom axioms with proofs.
Ruled out, with scope
  • Use the April 2026 four-prime proof as written to prune search.
    The asserted exact cardinality is false for overlapping tower congruences.
    Reopen only if: Supply and independently audit a corrected actual-region or weighted-region proof.
  • Treat the May 2026 Lean repository as an unconditional resolution.
    Its main theorem depends on two custom axioms not supplied by the cited BBMST results.
    Reopen only if: Replace both custom axioms with faithful proofs.
  • Odd LCM search avoiding both 9 and 15.
    Published BBMST work excludes the entire scope.
    Reopen only if: A demonstrated error in the published theorem.
  • Square-free or p<=73-square-free candidate search.
    Published BBMST work excludes the entire scope.
    Reopen only if: A demonstrated error in the published theorem.
Complete history

Attempts on this problem

2026-07-21 04:53 UTCOpen-problem program · 23 min

Distinct odd covering system

Mandatory source/status baseline, adversarial reconstruction of postdated claims, and differential validation of finite-witness checkers.

What this run accomplished

The problem remains open. Dense marking and direct streaming congruence evaluation agreed on all 1919 controls and failed closed at the period cap. The May 2026 Lean claim depends on custom axioms extending beyond BBMST's hypotheses. The April 2026 few-prime manuscript asserts a false Step 2 equality: tower classes 0 mod 3 and 0 mod 9 leave 6 residues, not 9/2. A normalized-ratio repair remains open.

Next: Prove or falsify the normalized actual-weight-region cylinder inequality using exact small controls.