Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.
Updated
Subject and independence
Role: independent reviewer in a fresh context, given only the commission. The reviewer took no part in writing the subject page, the reconstruction pages of the folder, or any earlier review of them. Charge: refutation of the author-recorded mathematics of one section.
Subject: page wiki/research/erdos_18/connections.md as it stood at
2026-09-28T13:50:48Z, section ## Shared lemmas, lines 47–243 (from the H2
heading to the line before ## Problem 304). The subject page is the lead page;
no other lead was named.
Read in full as of the same time: the section; the page's preamble (lines 1–46,
the standing sentence and the Conventions paragraph) as an input; the
reconstruction pages hughes_lemma_4_reconstruction.md,
hughes_theorem_1_reconstruction.md,
hughes_corollary_3_reconstruction.md, doorn_lemma_3_1_reconstruction.md,
doorn_lemma_3_3_reconstruction.md,
doorn_corollary_3_4_reconstruction.md,
doorn_proposition_4_1_reconstruction.md and
doorn_theorem_1_1_reconstruction.md of the folder, taken as premises at
their reviewed standing; the Statement paragraphs of
wiki/problems/divisors/E0018/_index.md,
wiki/problems/unit_fractions/E0304/_index.md and
wiki/problems/unit_fractions/E0293/_index.md; the provenance paragraphs of the
two library cards; the held PDFs, namely Hughes (2026) p. 2 on the page
image (Theorem 2 as quoted, Corollary 3, Lemma 4) with the extracted text
of pp. 1–3, and van Doorn (2026) pp. 2, 3 and 6 on the page images (Lemma
3.1 with its proof, Lemma 5.1 with its proof) with the extracted text of
pp. 1, 4 and 5 (the definitions of and , Lemma 3.3, Corollary
3.4, Proposition 4.1); docs/verification.md sections "Grading and claim
standing", "Audit checklist", "Whole-claim report" and the shared audit
checklist; docs/approach_vetting.md; docs/evidence.md section "Source
fidelity"; docs/math_authoring.md.
Exposures. (1) The three problem pages carry, between their Statement and
their first H2, a bold Status paragraph with known bounds and proof-claim
summaries, and their frontmatter desc and status fields; these were
printed together with the Statement and were read. No Current assessment
or Known results section was read. (2) The two library cards' generated
link rows, their Read status and Bears on paragraphs, and the opening of
the Hughes card's Overview were printed with the provenance paragraph and
were read. (3) The reconstruction pages carry Standing paragraphs that
describe their sources' standing; they were read as parts of those pages.
Nothing under any evidence/ folder, no _index.md, no other section's
review and no web search was consulted.
Restatement
Throughout, is the page's fresh-set count over , practical means every is a sum of distinct divisors of , is the divisor count and logarithms are natural unless subscripted.
S1 (Lemma A). Let be an integer such that for every odd prime dividing . Then (a) any two consecutive divisors of satisfy ; (b) by the consequence clause of the Lemma 4 page, the greedy expansion of every terminates and writes as a sum of distinct divisors of , so is practical; (c) ; (d) the hypothesis holds for for every , for for every , and for whenever it holds for , is an odd prime, and .
S2 (Lemma B). Let have property (a) of S1, let be real with , let be nonincreasing, and suppose every pair of consecutive divisors of with has . Put for . Then is nondecreasing, , and
with the constants , and absolute.
S3 (Lemma C). Let be integers with practical and . Then there are distinct integers greater than whose reciprocals sum to , of which are divisors of (in ) and are of the form with , each greater than . If , none of them equals .
S4 (Lemma C′). Let be a sufficiently large integer, the least integer with , the least prime not dividing , and if , else with . Then is practical, , , and . The parenthetical asserts and .
S5 (Lemma D, first inequality). For every practical and every chain , , with , in which every residue modulo is a sum of at most distinct divisors of , for each , hence for the sums over .
S6 (Lemma D, second inequality). Under the hypotheses of S5,
with as , where, as written ("uniformly over all such chains"), depends on neither the chain nor its seed .
S7 (Lemma D, "Hence" sentence). For every such chain, with the same ; this includes , where the chain is the seed alone.
S8 (closing paragraph). (a) No certificate built from Lemma 3.1 extensions alone from a fixed seed can prove for any fixed , or with , for all large along the chain. (b) In the van Doorn chain each step costs while . (c) Its primes of size make about one sixth of the maximal order . (d) is times .
Checklist
- Quantifiers and scope: defect in S6 and S7. "Let be practical" quantifies the seed universally and "uniformly over all such chains" removes the seed from the error term; under that reading S6 is false (F1) and S7 is unproved (F2). S1–S5 and S8 state their quantifiers exactly; S8 carries the "fixed seed" clause that S6 and S7 lack.
- Circularity: pass. No statement is assumed in its own proof; Lemma A reproves the ratio property rather than citing the Lemma 4 page's factorial case, and Lemma D's floor uses only counting and an external maximal-order bound.
- Model and convention changes: pass. The page's (over ) is the convention of the Lemma 4, Theorem 1 and Lemma 3.1 pages, and Lemma C uses it only for and , so the site's also serves. Lemma B transports the Theorem 1 count to an arbitrary profile; the bridge (facts (i) and (ii) and Lemma 4 hold for every ) was checked, not assumed from the shape of the formulas.
- Finite and statistical overreach: pass. No finite check is used as a proof on the page. Lemma C′'s "sufficiently large" is honest: gives , and , which is not practical. The exact checks reported below are attacks, not warrants.
- Uniformity: defect in S6 (F1). The proof's silently contains when the seed already exceeds the Wigert threshold. Lemma B's constants are explicit and absolute; Lemma A's bound is explicit; Lemma C′'s bound is explicit in .
- Extremal conclusions: pass with F2. The floor of Lemma D is stated in its own units, with the constant , and the "never below" of S7 is exactly the sentence that overreaches for unrestricted seeds. The arithmetic of S8(d), , was recomputed.
- Consequences and composition: pass except F2. Lemma A's "Consequently" was checked against the Lemma 4 page's consequence clause; Lemma C′ composes Lemma A with Lemma 3.1 and supplies every hypothesis of the latter (, seed practical, residues by one divisor each, total at most the seed, no summand divisible by ); Lemma D's "Hence" is F2.
- Computation: pass. The page computes only , , and ; all were recomputed. The reviewer's own exact checks are described under Strongest attack with their coverage.
- Reproduction: inapplicable. The section states no rerun command and no coverage claim.
- Source and verdict fidelity: pass with a note (F5). Lemma C matches Lemma 5.1 on the p. 6 image clause for clause; Lemma 3.1's interface matches p. 2; "pays per step" matches Corollary 3.4 on p. 5; and match p. 4; Lemma 4 and Corollary 3 match Hughes p. 2. The attribution "as the Problem 304 page records" lies outside the read set.
Weakest steps
W1 (Lemma D, the asymptotic floor). Write and , decreasing for . The maximal order of gives with ; fix and a threshold beyond which and . For , S5 gives , and because decreases, the left Riemann sum over dominates . If , the step has , so by S5 and its cost is at least , linear in ; this exceeds once , and otherwise . Either way , and letting gives S6 with depending only on . If , that is , nothing compensates the subtracted : the argument yields only , which is empty when is a bounded multiple of . The witness in F1 shows this is not a weakness of the proof but of the statement.
W2 (Lemma B, the upper range). For a nonterminal remainder with bracketing divisors , put , so . The map reverses the divisor order, so are consecutive divisors with ratio . From and (property (a) of S1) one has , hence ; fact (ii) of the Theorem 1 page ( forces ) gives , and gives . So the hypothesis applies to the mirror pair: , the last by monotonicity since . Lemma 4 at the actual remainder gives , so . The starts of the upper-range steps increase and lie in . With , an interval because is monotone, the starts in form a run, consecutive members of which differ by at least ; so starts in force , while , giving . There are at most classes. Adding the lower range (), the two endgames (each at most halving steps) and the terminal divisor gives , which is below the stated bound. The lower-range charging needs at the upper end of each step's interval to dominate the integrand, which nondecreasing supplies; the last lower-range step may leave and is counted by the .
W3 (Lemma C′, the second case). If , then because by the minimality of (for ). For with , , so together with would give , a contradiction; and gives . For the practicality and the cost, the residues modulo are each a single divisor of , hence of , not divisible by and of total , and the residue is the empty sum; this is the hypothesis of Lemma 3.1 with and , valid exactly when , that is , which with is . Applying Lemma 3.1 times from the practical number (Lemma A) gives and because . The condition holds for every : if every prime below divided , their product would be at most , which fails for , and has . For it fails (), which is the case above.
Strongest attack
S1. The attack looked for an meeting the hypothesis with a divisor gap above , concentrating on odd primes just below a power of two, where is close to (for example and ), and on the proof's step , which needs odd and is supplied by the case split. An exhaustive exact check of every satisfying the hypothesis confirmed the ratio property, that the greedy divisors are distinct and sum to for every , and that their number is at most ; the hypothesis is not vacuous ( fails it and has the consecutive divisors ). The factorial, lcm and cases were rederived, including for and the three values for . The attack failed.
S2. The attack targeted the direction of monotonicity in each range (the lower range bounds a descent by at the upper end of the step's interval, the upper range an ascent by at the lower end, which is why the dyadic classes are needed), the domain of at each evaluation (, , and all lie in when or ), the possibility of many starts in one class (excluded by the forced separation ), the boundary steps (the last lower-range step, counted by ; runs whose last ascent leaves the interval, which the count of starts ignores) and the constant bookkeeping, which has slack . The bookkeeping was also exercised on with read off the actual gaps and the least power of two admissible under the hypothesis: the greedy steps of sampled in each of the four ranges stayed within that range's bound. The attack failed.
S3. The attack targeted distinctness across the two groups (settled by ), the degenerate cases (empty second group) and (forced by ), and the last clause, which fails without : for and the representation is itself. An exhaustive exact-rational check over every practical , every and every confirmed the sum, the distinctness, the bound and the avoidance of when . The attack failed.
S4. The attack targeted the choice of (it must avoid , not ; the gcd computation shows why), the case for odd (the single residue ), the inequality (W3), and small : breaks the lemma (), so "sufficiently large" cannot be removed, while an exact computation of for the factorials and prime-power multiples involved confirmed every clause for . The attack failed.
S5. Each residue class needs its own representing subset, since a subset has one sum. The number of subsets of a -set with at most elements is . The attack failed.
S6. Witness: (practical by binary expansion), , , , since the residues modulo are the empty sum, the divisor and the divisor , with totals at most and no summand divisible by ; . The middle term of the display is , the left is , and the right is for any (about at ). The statement as written is refuted; W1 locates the gap. Restricted to seeds for a fixed , the proof of the page closes with the one-line addition that the subtracted is then , and no attack against that version succeeded.
S7. The witness of S6 does not refute S7, because . But for and unrestricted seed, S7 reads for every practical , a lower bound for that the page itself disclaims ("not a lower bound for ") and that no argument on the page supports; the counting bound gives only . No disproof is known to the reviewer. For seeds bounded by a fixed , S7 follows from the repaired S6 since .
S8. (a) follows from the repaired S6 with a constant. For (b), (c) and (d) the Lemma 3.3 and Proposition 4.1 pages give , a product of primes in with and , so and ; compares with , so and the maximal order is six times ; and . The van Doorn chain's certified cost with exceeds its own Lemma D sum by the factor and the universal floor by , consistently. The attack failed.
Premises
- Lemma 4 page: for whose consecutive divisors have ratio at most and a nonterminal remainder with bracketing divisors , and ; the compilation-supplied consequence that the greedy expansion of every terminates and writes as a sum of distinct divisors. Independently reviewed as of 2026-09-28T05:03:27Z per the commission; read in full; the source lemma checked on Hughes p. 2.
- Theorem 1 page: facts (i) ( forces ) and (ii) ( forces ), whose proofs use only that permutes the divisors, and the lower-range charging argument. Same standing; read in full.
- Corollary 3 page: the conventions and the windows named in the page's Conventions; not otherwise consumed by the section. Read in full.
- Lemma 3.1 page: for and practical , if every residue modulo is a sum of at most distinct divisors of with total at most and no summand divisible by , then is practical and . Same standing; read in full; statement and proof checked on van Doorn pp. 2–3.
- Lemma 3.3 page, Corollary 3.4 page, Proposition 4.1 page and Theorem 1.1 page: the definitions of , , , the cost per step, the construction and its size estimates, used only for S8(b)–(d). Same standing (claimed results, reconstructed); read in full; checked against van Doorn pp. 4–6.
- Hughes (2026), held: p. 2 read on the page image, pp. 1–3 in extracted text.
- van Doorn (2026), held: pp. 2, 3, 6 read on the page images, pp. 1, 4, 5 in extracted text. Lemma 5.1 (p. 6) states exactly S3 and is called well known there.
- Wigert's maximal order of , used by Lemma D in the form with : a classical theorem, not held in the library, imported by the page without a citation; the form is the standard one and was accepted.
- An elementary lower bound for the product of the primes below (Chebyshev type), silently behind the aside in Lemma C′; not held, not used by the proof (F4).
- The Statement paragraphs of Problems 18, 304 and 293 for the conventions , , , and ; read as stated.
- Explicit assumptions of this review: the reconstruction pages are taken as established at their reviewed standing, and the Lemma 3.1 page's result is consumed as a claimed result whose proof was nevertheless rechecked on the source pages because Lemma C′ and Lemma D rest on its interface.
Findings
F1 (required). Location: Lemma D, Statement, "where the tends to as uniformly over all such chains", together with "Let be practical". Defect: the second inequality is false when the seed is unrestricted; the proof handles the first index only when a step precedes it ("The step , if it exists"), and when it does not exist the subtracted is absorbed into without justification. Witness: , , , , for which the middle term is while the right side tends to infinity with . Replacement: "where, for each fixed , the tends to as uniformly over all such chains with ", and in the proof, after "the other steps contribute nonnegatively": "if , then and the subtracted term is ", with read as .
F2 (required). Location: Lemma D, Statement, "Hence the bound that such a chain certifies for is never below ." Defect: for unrestricted seeds this sentence, at , asserts the lower bound for every practical , which the page does not prove and elsewhere disclaims; the sentence is proved only for seeds bounded by a fixed , which is what the following paragraph's "from a fixed seed" means. Witness: none for a disproof; the defect is an unsupported inference. Replacement: "Hence, for chains from seeds , the bound that such a chain certifies for is never below ."
F3 (suggested). Location: Lemma D, Proof, "let be the least index with ". Defect: is not defined; the proof needs it to satisfy both for and , the latter so that decreases on the range of the Riemann sum. Replacement: define by these two properties before introducing .
F4 (note). Location: Lemma C′, Statement, "(so : the primes dividing have product at most , whence )". Defect: the "whence" imports a lower bound for the product of the primes below without saying so, and the proof uses only , which holds for every (W3); the lemma's "large" is still needed, as shows. Replacement: "(so for , since the primes below cannot all divide once )"; drop or mark it as an unused aside.
F5 (note). Location: Lemma C, preamble, "it is the transfer behind Erdős's 1950 bound and behind Vose's, as the Problem 304 page records". The attribution to the Problem 304 page lies outside this review's read set and was not checked; the note's own introduction (pp. 1–2) supports the mathematical attribution. No replacement proposed.
Verdict
- S1 (Lemma A): refutation-failed.
- S2 (Lemma B): refutation-failed.
- S3 (Lemma C): refutation-failed.
- S4 (Lemma C′): refutation-failed.
- S5 (Lemma D, first inequality): refutation-failed.
- S6 (Lemma D, second inequality with the uniform over all chains): refuted-as-stated, by the witness of F1; the same inequality with the seed bounded by a fixed constant survived every attack once the proof receives the one-line addition of F1.
- S7 (Lemma D, "Hence" sentence): proof defective; statement unresolved, for unrestricted seeds (F2); it follows from the repaired S6 for seeds bounded by a fixed constant.
- S8 (closing paragraph, fixed-seed obstruction and the van Doorn accounting): refutation-failed, its "from a fixed seed" being exactly the hypothesis the repaired S6 needs.
Limitations. Wigert's maximal order and the Berend–Harmse conventions were accepted as imported; the reconstruction pages were consumed at their reviewed standing and the note's results remain claimed; the exact checks cover only the stated finite ranges and warrant nothing beyond the derivations they accompany. This focused review assigns no tier and changes no status.