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Created May 25, 2026 21:23
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rrma erdos solver
From Table 1 of the paper. Here they are ranked by how well they fit the current RRMA setup:
---
Cluster 1 — Density (reuse #125 infrastructure directly)
┌─────────┬──────┬──────────────────────────────────────────────────────────────┬──────────────────────────────────┐
│ # │ Year │ Statement │ Technique │
├─────────┼──────┼──────────────────────────────────────────────────────────────┼──────────────────────────────────┤
│ 125 │ 1996 │ lowerDensity(A+B) = 0 for base-3/4 digit sets │ Dirichlet + inductive thinning ← │
│ │ │ │ running │
├─────────┼──────┼──────────────────────────────────────────────────────────────┼──────────────────────────────────┤
│ 741(i) │ 1994 │ If A+A has upper density, ∃ decomposition A=A₁⊔A₂ with both │ Upper density case analysis │
│ │ │ pieces positive upper density │ │
├─────────┼──────┼──────────────────────────────────────────────────────────────┼──────────────────────────────────┤
│ 741(ii) │ 1994 │ ∃ basis A of order 2 with A₁+A₁, A₂+A₂ bounded gaps for all │ Explicit rapidly growing │
│ │ │ splits │ sequence construction │
└─────────┴──────┴──────────────────────────────────────────────────────────────┴──────────────────────────────────┘
lowerDensity, upperDensity, liminf infrastructure from #125 carries over directly. Run these next — cheapest seed.
---
Cluster 2 — CRT / Block construction
┌────────┬──────┬───────────────────────────────────────────────────────────┬──────────────────────────────────────┐
│ # │ Year │ Statement │ Technique │
├────────┼──────┼───────────────────────────────────────────────────────────┼──────────────────────────────────────┤
│ 12(i) │ 1970 │ ∃ A ⊂ ℤ⁺ with a∤(b+c) and |A∩[1,N]|/√N > δ > 0 infinitely │ CRT + 3-AP avoiding sets │
│ │ │ often │ │
├────────┼──────┼───────────────────────────────────────────────────────────┼──────────────────────────────────────┤
│ 12(ii) │ 1970 │ Same divisibility constraint but |A∩[1,N]| ≫ N^{1-ε} │ CRT + 3-AP avoiding sets │
├────────┼──────┼───────────────────────────────────────────────────────────┼──────────────────────────────────────┤
│ 26* │ 1995 │ ∃ A with upperDensity(A+k) < 1-¼ for all k │ CRT + increasing primes + density │
│ │ │ │ bounds │
└────────┴──────┴───────────────────────────────────────────────────────────┴──────────────────────────────────────┘
Same proof skeleton — CRT is well covered in Mathlib. These three can share one blackboard.
---
Cluster 3 — Harder / different tooling
┌──────┬──────┬────────────────────────────────────────────────────────┬───────────────────────────────────────────┐
│ # │ Year │ Statement │ Technique │
├──────┼──────┼────────────────────────────────────────────────────────┼───────────────────────────────────────────┤
│ 138* │ 1981 │ Van der Waerden numbers: W(k+1)-W(k) → ∞ │ Greedy coloring + monochromatic │
│ │ │ │ intersection │
├──────┼──────┼────────────────────────────────────────────────────────┼───────────────────────────────────────────┤
│ 152 │ 1994 │ Large Sidon sets contain many isolated points in A+A │ Interior point bounds + quadruples │
├──────┼──────┼────────────────────────────────────────────────────────┼───────────────────────────────────────────┤
│ 846 │ 1992 │ ∃ infinite A with no finite union of non-collinear │ Fast-growing sequence + algebraic map │
│ │ │ subsets │ │
└──────┴──────┴────────────────────────────────────────────────────────┴───────────────────────────────────────────┘
These need Ramsey theory, Sidon set lemmas, or algebraic geometry tooling — less Mathlib coverage, harder seeds.
---
Recommended order:
#125 (now) → #741(ii) → #741(i) → #12(i) → #12(ii) → #26* → #152 → #138* → #846
741(ii) is the immediate next — it's a construction proof (explicit sequence), easiest to formalize, and the density
infrastructure is already built. Seed it while #125 is still running.
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