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Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.

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Subject and independence

Role. The reviewer worked in a fresh context from the commissioning assignment alone, took no part in writing the section, the lead, the Tools section or the reconstruction pages, and had no contact with their author or with the reviewers of the other sections. The charge was refutation. No tier is assigned and no status changes.

Subject. The source as it stood on 2026-09-28T13:50:48Z (called "the commit" below). The section "## Problem 597: graph targets" of wiki/research/erdos_1171/connections.md, lines 318--409 (the H2 at line 318 up to the line before the next H2 at line 410), and the lead page wiki/research/leads/graph_targets_under_martin_axiom/_index.md, read whole. Line numbers below refer to these two files at this commit.

Reading and depth.

  • The section, every sentence, with each deduction re-derived.
  • The page's Tools section (lines 32--124) as input: the interfaces of (T1), (T2), (T3) and (T4) were confirmed at each use, and the proof of (T4) was re-derived because (T3), which the section uses, is stated as its constant case. (T5) is not used by the section and was not checked.
  • The reconstruction pages lemma_2_1_reconstruction.md and theorem_3_1_reconstruction.md (premises), read whole, checked for the hypotheses under which the section uses them.
  • The statement blocks of the problem pages E0597, E1171 and E0924.
  • Library material where a source theorem is invoked: the cards and result pages of Baumgartner (1989), Baumgartner and Hajnal (1987), Folkman (1970), Chen, Garti and Weinert (2018), Gao (2026) and Komjáth (2025); the held PDFs of Chen, Garti and Weinert (p. 5 page image and text layer, and the first page for its identity), Folkman (printed p. 19 text layer, printed p. 20 page image) and Komjáth (printed pp. 425--426 and 442--443 page images).
  • docs/verification.md (Whole-claim report, Audit checklist, Grading and claim standing), docs/approach_vetting.md, docs/evidence.md (Source fidelity) and docs/math_authoring.md.

Exposures. (1) The three problem pages have no separate Statement heading; the block read for each ran from its H1 to its "Current assessment" heading and so included the page's Status line and Source paragraph. For E1171 that paragraph quotes the catalog's status wording and mentions a discussion thread and a proof-claim tab; for E0924 the Status paragraph is where the Nešetřil--Rödl theorem is recorded, and it was read for that record. (2) A heading listing showed that E0597 carries "Current assessment", "Progress" and "Known Results" sections; their contents were not read. (3) A search for the quoted sentences ran over the whole connections page and returned four one-line fragments of other sections (lines 218, 287, 452 and 542); nothing else of those sections was read. (4) The library cards were read whole, including their read-status and standing lines. (5) A working-tree status listing showed the file names of parallel reviews of other sections and folders; none was opened. Nothing under any evidence/ folder, no folder _index.md, no existing review or grade, and no web content was read; the catalog page for Problem 597 was not consulted, so the section's three catalog attributions are recorded here as unverified.

Restatement

Conventions (S1, not a claim). Ordinals are von Neumann ordinals; [X]2[X]^2 is the set of two-element subsets. For an ordinal γ\gamma, an ordinal β\beta and targets H1,…,HkH_1,\ldots,H_k, each an order type or a graph, γ→(β,H1,…,Hk)k+12\gamma\to(\beta,H_1,\ldots,H_k)^2_{k+1} means: every c:[γ]2→{0,…,k}c:[\gamma]^2\to\{0,\ldots,k\} has X⊆γX\subseteq\gamma with otp⁡(X)=β\operatorname{otp}(X)=\beta and c≡0c\equiv0 on [X]2[X]^2, or for some ii a copy of HiH_i in color ii, a copy being a subset of type HiH_i for an order type and, for a graph, an injection of the vertices of HiH_i into γ\gamma under which every edge of HiH_i goes to a pair of color ii (subgraph copies, not induced). For k=1k=1 and a graph GG this says: every graph on γ\gamma has an independent set of type β\beta or contains GG as a subgraph. (Q1) asks whether ω12→(ω1ω,G)2\omega_1^2\to(\omega_1\omega,G)^2 for every graph GG on at most ℵ1\aleph_1 vertices with no K4K_4 and no Kℵ0,ℵ0K_{\aleph_0,\aleph_0} subgraph; (Q2) asks the same for finite GG, for which the Kℵ0,ℵ0K_{\aleph_0,\aleph_0} exclusion is vacuous. The problem page carries status open. Two conventions bear on everything below: a finite nn-element set homogeneous in color 11 is the same object as a copy of KnK_n in color 11, and a positive relation on an ordinal γ\gamma transfers to every ordinal γ′≥γ\gamma'\ge\gamma by restriction of the coloring (T2), while a negative relation transfers only downward.

  • S2. Assume MAℵ1\mathrm{MA}_{\aleph_1} and the imported theorem that ω1ω→(ω1ω,n)2\omega_1\omega\to(\omega_1\omega,n)^2 for every finite nn. Then for every finite graph GG, ω1ω→(ω1ω,G)2\omega_1\omega\to(\omega_1\omega,G)^2.
  • S3. Under the same hypotheses, for every finite graph GG, ω12→(ω1ω,G)2\omega_1^2\to(\omega_1\omega,G)^2. Hence in every model of MAℵ1\mathrm{MA}_{\aleph_1} the answer to (Q2) is yes for every finite GG, K4K_4-free or not; with the relative consistency of MAℵ1\mathrm{MA}_{\aleph_1} (Theorem C), ZFC does not refute (Q2). The color-merging lemma is not used.
  • S4. Under the same hypotheses, for every finite k≥1k\ge1 and finite graphs G1,…,GkG_1,\ldots,G_k, ω12→(ω1ω,G1,…,Gk)k+12\omega_1^2\to(\omega_1\omega,G_1,\ldots,G_k)^2_{k+1}, with color ii carrying GiG_i; once by (T3) at α=ω1ω\alpha=\omega_1\omega followed by restriction, and once from the imported theorem at nn equal to the multicolor Ramsey number of the cliques on the GiG_i, followed by the finite Ramsey theorem and restriction.
  • S5. Under any hypothesis that gives ω1ω→(ω1ω,Gi)2\omega_1\omega\to(\omega_1\omega,G_i)^2 for i=1,…,ki=1,\ldots,k, with the GiG_i graphs of any size, ω12→(ω1ω,G1,…,Gk)k+12\omega_1^2\to(\omega_1\omega,G_1,\ldots,G_k)^2_{k+1}; the finite Ramsey bridge of S4 does not give this when some GiG_i is infinite.
  • S6 (obstruction). The mechanism of the folder, Lemma 2.1 with its general form (T4) and the transfers (T2), does not produce the two-color relation ω12→(ω1ω,G)2\omega_1^2\to(\omega_1\omega,G)^2 from any input weaker than that relation: (T4) with one link is its own hypothesis, and any relation γ→(β,G)2\gamma\to(\beta,G)^2 with γ≤ω12\gamma\le\omega_1^2 and β≥ω1ω\beta\ge\omega_1\omega that (T2) could feed in already implies the target.
  • S7. For every finite k≥1k\ge1 there is a finite K4K_4-free graph FkF_k such that every coloring of its edges with kk colors has a monochromatic triangle: for k=2k=2 by Folkman's Theorem 1, for every kk by the theorem of Nešetřil and Rödl.
  • S8. For every finite k≥1k\ge1 and every such FkF_k: if ω12→(ω1ω,Fk)2\omega_1^2\to(\omega_1\omega,F_k)^2, then ω12→(ω1ω,3,…,3)k+12\omega_1^2\to(\omega_1\omega,3,\ldots,3)^2_{k+1} with kk triangle targets. Consequently, if ZFC proves (Q2) at every FkF_k, ZFC proves the relation of Problem 1171 for every kk; every model of ω12↛(ω1ω,3,…,3)k+12\omega_1^2\not\to(\omega_1\omega,3,\ldots,3)^2_{k+1} is a model in which (Q2) fails at the K4K_4-free finite graph FkF_k; and (Q2) at F3F_3 implies the case k=3k=3 of Problem 1171.
  • S9. In the converse direction, the relation of Problem 1171 yields a two-color relation ω12→(ω1ω,G)2\omega_1^2\to(\omega_1\omega,G)^2 only for graphs GG that are subgraphs of a triangle. (Read as: by leaving colors unused and weakening the target under (T2); see F4 for the stronger reading.)
  • S10. In any model, a positive answer to (Q1) implies that every graph on ω12\omega_1^2 with no independent set of type ω1ω\omega_1\omega contains every admissible GG as a subgraph; the negative relation ω12↛(ω1ω,Kℵ0,ℵ0)2\omega_1^2\not\to(\omega_1\omega,K_{\aleph_0,\aleph_0})^2 attributed to Baumgartner (hypothesis unrecorded) is exactly the failure of that condition at Kℵ0,ℵ0K_{\aleph_0,\aleph_0}.
  • S11. The route of S2--S3 reaches (Q1) only for those infinite admissible GG with ω1ω→(ω1ω,G)2\omega_1\omega\to(\omega_1\omega,G)^2 under MAℵ1\mathrm{MA}_{\aleph_1}; the imported theorem is stated for finite nn only, and nothing held in the corpus decides any infinite case.
  • S12. Investigation (ii) of the section and step 2 of the lead. (a) If MAℵ1\mathrm{MA}_{\aleph_1} gives ω1ω→(ω1ω,G)2\omega_1\omega\to(\omega_1\omega,G)^2 for an admissible GG, then (Q1) at GG is not disprovable in ZFC. (b) If the extension fails for some admissible GG, "a counterexample GG under MAℵ1\mathrm{MA}_{\aleph_1}", then (Q1) has no positive answer in ZFC and GG is a third necessary exclusion.
  • S13. Investigation (iii) of the section and step 3 of the lead. A positive answer to (Q2) at F3F_3 settles the case k=3k=3 of Problem 1171; a consistent negative answer to that case "refutes (Q2) at F3F_3".
  • S14 (provenance and standing sentences, not mathematics). The imported theorem is taken "from the zbMATH review and one refereed restatement"; the lead reads copies as subgraph copies, "the convention of the lemma page and of Komjáth's survey"; the lead cites a CH obstruction recorded in the first section of the connections page, which is outside this review's read set and is not assessed here.

Checklist

  • Quantifiers and scope. S2--S8 carry their quantifiers correctly: the universal over finite GG in S3 holds in one model at a time, so "not disprovable" is the right modality; S8 is stated per kk with any choice of FkF_k. One defect: S12(b) moves from a failure on the initial segment ω1ω\omega_1\omega to a conclusion about ω12\omega_1^2, a change of the ordinal in the relation with no bridge (F1).
  • Circularity. None. S6 observes that (T4) at one link is the target itself; that is an obstruction statement, not a circular use.
  • Model and convention changes. The subgraph reading of copies is declared and used consistently in S2, S8 and S10. Two silent identifications are harmless but should be explicit: the ordinal target nn read as the graph KnK_n in S2, and (T1)'s "all of whose pairs" read as "all of whose edges" for graph targets (F6). The lead misattributes the convention to the lemma reconstruction page (F5).
  • Finite and statistical overreach. None. The finite Ramsey theorem and the existence of FkF_k are used for their exact finite content.
  • Uniformity. The Ramsey number in S4 depends on G1,…,GkG_1,\ldots,G_k and the graph FkF_k depends on kk; both dependences are stated. No constant is claimed uniform.
  • Extremal conclusions. "At least as strong" in S8 is an implication and holds. "Only for subgraphs of a triangle" in S9 is exact for the weakening route but, read as an independence statement, is unsupported (F4).
  • Consequences and composition. Every "hence" was checked separately. S3 inherits the unproved premise (the imported theorem at full strength) and says so; S12(b) does not follow from its hypothesis (F1); S13's "refutes" overstates a consistency conclusion (F2).
  • Computation. Inapplicable: no computation is used or claimed.
  • Reproduction. Inapplicable: no rerun command or coverage claim.
  • Source and verdict fidelity. The restatement of the imported theorem was checked on the page image of Chen, Garti and Weinert (p. 5): it reads that ZFC with MAℵ1\mathrm{MA}_{\aleph_1} implies ω1ω→(ω1ω,n)2\omega_1\omega\to(\omega_1\omega,n)^2 for all natural numbers nn, as the section says. Folkman's Theorem 1 and the editor's footnote were checked on the page images. Komjáth's record of the Baumgartner--Hajnal relations and of the Nešetřil--Rödl theorem was checked on the page images. The word "refereed" for the restatement is not supported by the held artifact, an arXiv preprint, or by its library card (F3).

Weakest steps

W1 (S2--S3): from the ordinal target nn to a graph target, and up to ω12\omega_1^2. Let GG be a finite graph with vertex set of size nn; if n=0n=0 or n=1n=1 the copy is trivial, so let n≥2n\ge2. Let c:[ω1ω]2→{0,1}c:[\omega_1\omega]^2\to\{0,1\}. The imported theorem gives X⊆ω1ωX\subseteq\omega_1\omega of type ω1ω\omega_1\omega with c≡0c\equiv0 on [X]2[X]^2, or an nn-element YY with c≡1c\equiv1 on [Y]2[Y]^2. In the second case any bijection from the vertices of GG onto YY sends every edge of GG to a pair of color 11, so it is a copy of GG in color 11; non-edges of GG impose no condition under the subgraph reading. This is S2. Now let c:[ω12]2→{0,1}c:[\omega_1^2]^2\to\{0,1\}. Since ω1ω<ω12\omega_1\omega<\omega_1^2, the ordinal ω1ω\omega_1\omega is the set of ordinals below it, a subset of ω12\omega_1^2, and c↾[ω1ω]2c\upharpoonright[\omega_1\omega]^2 is a two-coloring to which S2 applies. A set X⊆ω1ωX\subseteq\omega_1\omega of type ω1ω\omega_1\omega has the same order as a subset of ω12\omega_1^2 (membership in both), so its type is unchanged, and a copy of GG inside ω1ω\omega_1\omega is a copy inside ω12\omega_1^2 with the same colors. This is S3; nothing beyond ω1ω⊆ω12\omega_1\omega\subseteq\omega_1^2 is used. The consistency step is Theorem C: a model of MAℵ1\mathrm{MA}_{\aleph_1} satisfies (Q2) for every finite GG simultaneously, so ZFC, if consistent, cannot prove the negation of (Q2). Composition: S3 is conditional on the imported theorem at full strength; if only n=3n=3 were available, S2 would cover exactly the subgraphs of a triangle, as the lead's provisional premise says.

W2 (S8): the Folkman merge. Fix k≥1k\ge1 and FkF_k as in S7, and assume ω12→(ω1ω,Fk)2\omega_1^2\to(\omega_1\omega,F_k)^2. Let c:[ω12]2→{0,…,k}c:[\omega_1^2]^2\to\{0,\ldots,k\} and put c′(p)=0c'(p)=0 if c(p)=0c(p)=0 and c′(p)=1c'(p)=1 otherwise. The assumed relation applied to c′c' gives either XX of type ω1ω\omega_1\omega with c′≡0c'\equiv0, hence c≡0c\equiv0, on [X]2[X]^2, which is the color-00 alternative of the target relation; or an injection φ\varphi of the vertices of FkF_k into ω12\omega_1^2 sending each edge ee to a pair φ(e)\varphi(e) with c(φ(e))∈{1,…,k}c(\varphi(e))\in\{1,\ldots,k\}. Then e↦c(φ(e))e\mapsto c(\varphi(e)) is a kk-coloring of the edges of FkF_k, so some triangle {u,v,w}\{u,v,w\} of FkF_k has its three edges of one color j≥1j\ge1; the three points φ(u),φ(v),φ(w)\varphi(u),\varphi(v),\varphi(w) are distinct and all three pairs among them have cc-color jj, a triangle of color jj. The merge never uses that FkF_k is K4K_4-free; that property only places FkF_k inside the class (Q2) asks about, which is what the consequences need. The contrapositive gives the model statement, and k=3k=3 gives the last clause.

W3 (S4--S5): (T4) with graph targets, re-derived. Let γj−1→(γj,Hj)2\gamma_{j-1}\to(\gamma_j,H_j)^2 for j=1,…,kj=1,\ldots,k, with the HjH_j arbitrary graphs or order types. Claim: γ0→(γk,H1,…,Hk)k+12\gamma_0\to(\gamma_k,H_1,\ldots,H_k)^2_{k+1}. For k=1k=1 this is the hypothesis. For the step, let cc use the colors 0,…,k+10,\ldots,k+1 and let c′c' send k+1k+1 to 00 and fix the other colors. The case kk gives a copy of some HjH_j (j≤kj\le k) in c′c'-color jj, which is cc-color jj since c′=cc'=c off {0,k+1}\{0,k+1\}; or Y⊆γ0Y\subseteq\gamma_0 of type γk\gamma_k with c[ [Y]2 ]⊆{0,k+1}c[\,[Y]^2\,]\subseteq\{0,k+1\}. In the latter case transport γk→(γk+1,Hk+1)2\gamma_k\to(\gamma_{k+1},H_{k+1})^2 to YY along the order isomorphism π:γk→Y\pi:\gamma_k\to Y (pull the coloring back, take the homogeneous set or copy in γk\gamma_k, push it forward; π\pi is injective, preserves order and carries pairs to pairs, so types and copies are preserved) and apply it to the two-coloring of [Y]2[Y]^2 in which k+1k+1 is read as 11. The result is a subset of YY of type γk+1\gamma_{k+1} of cc-color 00 or a copy of Hk+1H_{k+1} of cc-color k+1k+1. No property of the targets is used, so the constant case (T3) holds for graphs of any size, and with α=ω1ω\alpha=\omega_1\omega and the restriction of W1 it gives S4 and S5. The Ramsey alternative in S4: with nin_i the number of vertices of GiG_i and n=R(n1,…,nk)n=R(n_1,\ldots,n_k), merge colors 1,…,k1,\ldots,k, obtain an nn-element set in the merged color, split it back and find an nin_i-clique of color ii, which contains a copy of GiG_i. For infinite GiG_i no finite nn contains a copy, so that bridge stops, as S5 says; the induction bridge does not.

Strongest attack

  • S2, S3. Attack 1: the direction of transfer. Positive relations restrict upward (W1); the attack would need a downward use, and there is none. Attack 2: the copy convention. Under induced copies S2 fails already for GG the graph on two vertices with no edge, since an nn-element set of color 11 contains no induced non-edge; the section and lead declare subgraph copies, which the problem's exclusion of Kℵ0,ℵ0K_{\aleph_0,\aleph_0} as a subgraph also presupposes, so the attack hits a convention, not the argument. Attack 3: a finite GG with ω12↛(ω1ω,G)2\omega_1^2\not\to(\omega_1\omega,G)^2 under MAℵ1\mathrm{MA}_{\aleph_1}. Impossible given the imported theorem, since G⊆KnG\subseteq K_n; the only exposure is the theorem's full strength, which the section discloses as a premise. Attack 4: the CH negative relation for K4K_4 against S3's "whether or not GG is K4K_4-free". No conflict: the two hold in different models, and the held restatement (Chen, Garti and Weinert, p. 5) draws the same conclusion, that the negative relation needs a hypothesis. The attacks failed.
  • S4, S5. Attack: a hidden use of finiteness in (T3). The re-derivation W3 shows none. Attack on the Ramsey alternative: the multicolor Ramsey number must be taken for the cliques KniK_{n_i}, not for the GiG_i themselves, which is what the sentence says. Failed.
  • S6. Attack: exhibit an input of the mechanism strictly weaker than (Q2) at GG that still yields it. Every input the tools accept is a two-color relation γ→(β,G)2\gamma\to(\beta,G)^2 that (T2) turns into the target when γ≤ω12\gamma\le\omega_1^2 and β≥ω1ω\beta\ge\omega_1\omega, and the induction only adds colors. Failed; the statement is modest and exact.
  • S7. Checked against Folkman's Theorem 1 on the page image (f(3,3)=3f(3,3)=3, so a graph of clique number 33, hence K4K_4-free, lies in Γ(3,3)\Gamma(3,3)) and against Komjáth's record of the Nešetřil--Rödl theorem (for YY finite without Kk+1K_{k+1} and r<ωr<\omega, a finite XX omitting Kk+1K_{k+1} in which every rr-coloring of the edges has a monochromatic induced copy of YY; take Y=K3Y=K_3). The second is second-hand, as the section and Problem 924 say. Failed.
  • S8. Attack: the monochromatic triangle of FkF_k might not be a triangle of ω12\omega_1^2 because non-edges of FkF_k are uncolored. A triangle of FkF_k consists of three edges, all of which are colored, so the image is a triangle in the ordinal (W2). Attack: the merged relation is the wrong instance of (Q2) because FkF_k might contain Kℵ0,ℵ0K_{\aleph_0,\aleph_0}; it is finite. Failed.
  • S9. Attack on the literal reading: the sentence "yields (Q2) only for subgraphs of a triangle" asserts, for every other GG, that the relation of Problem 1171 does not give (Q2) at GG. No argument is offered for that, and none is available here: it would need, for each such GG, a model of the Problem 1171 relations in which (Q2) fails at GG, and for K4K_4-free GG such as C4C_4 nothing held says whether ZFC proves (Q2) at GG outright. Under the route reading the statement is exact. The refutation of the literal reading is not a counterexample but the absence of any proof; filed as F4.
  • S10. Attack: "necessary" hides a stronger claim. The condition is in fact equivalent to (Q1) in the model, by unfolding the relation, so "necessary" is true and weaker than what holds. The identification of the Kℵ0,ℵ0K_{\aleph_0,\aleph_0} exclusion with a failure of the condition is exactly the imported negative relation, whose hypothesis the section correctly leaves open. Failed.
  • S11. Attack: find a held result deciding an infinite case. None of the held or cited material states a relation ω1ω→(ω1ω,G)2\omega_1\omega\to(\omega_1\omega,G)^2 or ω12→(ω1ω,G)2\omega_1^2\to(\omega_1\omega,G)^2 for an infinite GG. Failed as a statement about the corpus; see F7 for what the sentence must not be read as.
  • S12. (a) holds by S3's argument: a positive relation on ω1ω\omega_1\omega restricts upward. (b) is where the attack succeeded. The hypothesis, read in the sentence's own context ("whether the proof of ω1ω→(ω1ω,n)2\omega_1\omega\to(\omega_1\omega,n)^2 extends"), is ω1ω↛(ω1ω,G)2\omega_1\omega\not\to(\omega_1\omega,G)^2 in a model of MAℵ1\mathrm{MA}_{\aleph_1}; the conclusion needs ω12↛(ω1ω,G)2\omega_1^2\not\to(\omega_1\omega,G)^2 in some model. A negative relation does not pass from ω1ω\omega_1\omega to ω12\omega_1^2: the witness is G=K3G=K_3 under CH, where ω1ω↛(ω1ω,3)2\omega_1\omega\not\to(\omega_1\omega,3)^2 (Erdős and Hajnal, as the theorem page and the Baumgartner card record from the review) while ω12→(ω1ω,3)2\omega_1^2\to(\omega_1\omega,3)^2 is a theorem of ZFC (the ZFC relation ω12→(ω1ω,3,3)2\omega_1^2\to(\omega_1\omega,3,3)^2 with one color unused; Komjáth p. 425 attributes the two-color instance to Erdős and Hajnal). The witness is not an instance of the sentence's exact hypothesis, which names MAℵ1\mathrm{MA}_{\aleph_1}, so the verdict is not a disproof of the conclusion but a missing bridge: proof defective; statement unresolved.
  • S13. The first clause is S8 at k=3k=3. The second: from a model of ω12↛(ω1ω,3,3,3)2\omega_1^2\not\to(\omega_1\omega,3,3,3)^2, S8 gives a model in which (Q2) fails at F3F_3, hence that ZFC does not prove (Q2) at F3F_3. It does not give a ZFC disproof, which "refutes" suggests. Filed as F2; the intended consistency reading survives.

Premises

  • Lemma 2.1 reconstruction (lemma_2_1_reconstruction.md, premise at its reviewed standing, read whole). Interface: for an ordinal α\alpha, α→(α,3)2\alpha\to(\alpha,3)^2 implies α→(α,3,…,3)k+12\alpha\to(\alpha,3,\ldots,3)^2_{k+1} for every finite k≥1k\ge1; its fact 1 (transport along an order isomorphism) and fact 2 (relabeling). The section uses it only through the Tools section and to say it is not needed for S3; its convention covers ordinal targets only.
  • Theorem 3.1 reconstruction (theorem_3_1_reconstruction.md, premise, read whole). Interface used: Steps 2 and 3, the restriction of a coloring of [ω12]2[\omega_1^2]^2 to [ω1ω]2[\omega_1\omega]^2 and the reading of the result in ω12\omega_1^2, with its general remark that a subset of the right type suffices; Theorem A (the imported theorem at n=3n=3); Theorem C (relative consistency of MAℵ1\mathrm{MA}_{\aleph_1}); and its fidelity note that CH gives ω1ω↛(ω1ω,3)2\omega_1\omega\not\to(\omega_1\omega,3)^2, used as the witness in F1.
  • Tools (T1)--(T4) (connections.md, lines 38--93; proofs owned by another reviewer). Interfaces confirmed; (T4) re-derived in W3 with graph targets. (T1)'s phrase "all of whose pairs have color ii" was read as "edges" for graph targets (F6).
  • Baumgartner (1989), main theorem. Not held. Interface: MAℵ1\mathrm{MA}_{\aleph_1} implies ω1ω→(ω1ω,n)2\omega_1\omega\to(\omega_1\omega,n)^2 for every finite nn, two colors, the large target in color 00. Read through the card and result page (which cite the zbMATH review, not read here) and the introduction of Chen, Garti and Weinert, p. 5, page image. The card and the section call the restatement refereed; the held file is arXiv:1801.00238v1, and its own card records an arXiv preprint (F3).
  • Baumgartner and Hajnal (1987), negative relation. Not held. Interface: CH gives ω12↛(ω1ω,4)2\omega_1^2\not\to(\omega_1\omega,4)^2. Result page read; Komjáth pp. 425 and 442, page images.
  • Baumgartner and Hajnal (1987), positive relation. Not held. Interface: ω12→(ω1ω,3,3)2\omega_1^2\to(\omega_1\omega,3,3)^2 in ZFC. Result page read; Komjáth pp. 425 and 442, page images. Used only for the witness in F1.
  • Erdős and Hajnal, CH negative relation. Not held; ω1ω↛(ω1ω,3)2\omega_1\omega\not\to(\omega_1\omega,3)^2 under CH, as reported on the theorem page, the Baumgartner card and its result page from the review. Used only for the witness in F1.
  • Folkman (1970), Theorem 1. Held; f(k1,k2)=max⁡(k1,k2)f(k_1,k_2)=\max(k_1,k_2) for k1,k2≥2k_1,k_2\ge2, with the definitions of p. 19 (finite graphs; Γ\Gamma; the dimension δ\delta). Printed p. 20 page image and p. 19 text layer read; proof not read.
  • Nešetřil and Rödl (1976). Not held. Interface as recorded on Problem 924 and by Komjáth p. 442 (page image): for a finite YY with no Kk+1K_{k+1} and r<ωr<\omega there is a finite XX omitting Kk+1K_{k+1} such that every rr-coloring of its edges has a monochromatic induced copy of YY. Second-hand at both places.
  • Solovay and Tennenbaum (1971). Not held; Theorem C on the theorem page.
  • Problem statements of E0597, E1171 and E0924 at this commit.
  • Catalog page for Problem 597. Not read (web excluded); the section's attributions to it (the Erdős--Hajnal relation, the original K4K_4-free formulation, Baumgartner's Kℵ0,ℵ0K_{\aleph_0,\aleph_0} relation) are unverified here; Komjáth p. 425 supports the first.
  • Explicit assumptions. MAℵ1\mathrm{MA}_{\aleph_1} for S2--S4; the imported theorem at full strength for S2--S4; subgraph copies throughout.

Findings

  • F1 (required). Location: section lines 394--399, "(ii) Under MAℵ1\mathrm{MA}_{\aleph_1}, whether the proof of ω1ω→(ω1ω,n)2\omega_1\omega\to(\omega_1\omega,n)^2 extends to countable, then ℵ1\aleph_1-sized, K4K_4-free and Kℵ0,ℵ0K_{\aleph_0,\aleph_0}-free GG: ... a negative outcome, a counterexample GG under MAℵ1\mathrm{MA}_{\aleph_1}, shows that (Q1) has no positive answer in ZFC and names a third necessary exclusion"; lead lines 135--140, "determine whether the proof for finite nn extends ... A negative outcome, a counterexample GG under MAℵ1\mathrm{MA}_{\aleph_1}, shows that (Q1) has no positive answer in ZFC and names a third necessary exclusion." Defect: the investigation is about the relation on ω1ω\omega_1\omega, so its negative outcome is ω1ω↛(ω1ω,G)2\omega_1\omega\not\to(\omega_1\omega,G)^2 in a model of MAℵ1\mathrm{MA}_{\aleph_1}; the conclusion needs ω12↛(ω1ω,G)2\omega_1^2\not\to(\omega_1\omega,G)^2 in some model, and a negative relation does not transfer from the initial segment to ω12\omega_1^2. Witness: under CH, ω1ω↛(ω1ω,3)2\omega_1\omega\not\to(\omega_1\omega,3)^2 while ω12→(ω1ω,3)2\omega_1^2\to(\omega_1\omega,3)^2 holds in ZFC, so the same pattern of inference at G=K3G=K_3 from CH would conclude falsely that Problem 597 at K3K_3 has no positive ZFC answer. Replacement: "a negative outcome shows only that this route does not cover GG; (Q1) has no positive answer in ZFC, and GG is a third necessary exclusion, if some model satisfies ω12↛(ω1ω,G)2\omega_1^2\not\to(\omega_1\omega,G)^2 for an admissible GG, which a failure on ω1ω\omega_1\omega does not give."
  • F2 (suggested). Location: section lines 400--402, "a consistent negative answer for that case refutes (Q2) at F3F_3"; lead lines 141--143, "a consistent negative answer to that case refutes (Q2) at F3F_3." Defect: the consequence proved (S8) is that (Q2) fails at F3F_3 in every model of ω12↛(ω1ω,3,3,3)2\omega_1^2\not\to(\omega_1\omega,3,3,3)^2, hence is not a theorem of ZFC; "refutes" reads as a ZFC disproof. Replacement: "shows that (Q2) at F3F_3 is not provable in ZFC."
  • F3 (suggested). Location: section lines 336--338, "the statement is taken from the zbMATH review and one refereed restatement"; lead lines 106--107, "rests on the review and one refereed restatement." Defect: the held restatement is the file arXiv:1801.00238v1 of Chen, Garti and Weinert, dated 31 December 2017, which its library card records as an arXiv preprint; nothing held establishes that it was refereed, and the page's own scope rule cites sources at the standing their library pages record. The Baumgartner (1989) card is the origin of the word. Witness: the first page of the held PDF and the Chen, Garti and Weinert card. Replacement: "one held restatement (an arXiv preprint)", or record the publication data on that card first and cite it at that standing.
  • F4 (suggested). Location: section lines 379--380, "The converse implication gives nothing: the relation of Problem 1171 yields (Q2) only for subgraphs of a triangle." Defect: read literally, "only for" claims that no other GG is reached, an independence statement with no argument; what is shown is that target weakening reaches exactly the subgraphs of a triangle. Replacement: "In the converse direction, target weakening gives (Q2) exactly for the subgraphs of a triangle; whether the relation of Problem 1171, or ZFC alone, gives (Q2) for any other GG is not addressed here."
  • F5 (note). Location: lead lines 110--112, "the convention of the lemma page and of Komjáth's survey." Defect: the lemma reconstruction page defines the relation for ordinal targets only; the subgraph convention for graph targets is (T1) in the Tools section of the connections page. Komjáth's usage (K4≰XK_4\not\le X for subgraph containment, and the reformulation of the CH relation as a K4K_4-free graph on ω12\omega_1^2 without an independent set of type ω1ω\omega_1\omega) is consistent with it. Replacement: cite (T1) of the connections page in place of the lemma page.
  • F6 (note). Location: Tools (T1), lines 42--43, "a copy of HiH_i all of whose pairs have color ii"; section lines 339--341, "GG embeds in KnK_n, so ω1ω→(ω1ω,G)2\omega_1\omega\to(\omega_1\omega,G)^2 by (T2)". Defect: for a graph target the pairs meant are the edges of the copy, as S8 and the lead's definition use it, and the (T2) step replaces the ordinal target nn by a graph, which (T2) states only for a target embedding in a target of the same kind. Both are harmless once the identification of an nn-element homogeneous set with a copy of KnK_n is written. Replacement: say "all of whose edges have color ii" in (T1), and in the section "an nn-element set homogeneous in color 11 is a copy of KnK_n in color 11, which contains a copy of GG".
  • F7 (note). Location: section lines 384--385, "nothing held decides the infinite case." Not a defect: the sentence is true of the corpus. It should not be read as "nothing is known". The reviewer records, from memory and outside the held corpus, that the classical theorem of Erdős and Hajnal that a graph of uncountable chromatic number contains Kn,ℵ1K_{n,\aleph_1} for every finite nn would give ZFC instances of (Q1) at G=Kn,ℵ1G=K_{n,\aleph_1} (bipartite, hence K4K_4-free, and Kℵ0,ℵ0K_{\aleph_0,\aleph_0}-free): a graph on ω1ω\omega_1\omega that is a countable union of independent sets has an independent set of type ω1ω\omega_1\omega, because each block of type ω1\omega_1 meets some class in an uncountable set and one class serves infinitely many blocks, so a graph with no such independent set has uncountable chromatic number. This is offered for investigation (ii), is not part of the verdict, and needs the source before use.

Verdict

  • S1: not a claim (conventions).
  • S2: refutation-failed, conditional on MAℵ1\mathrm{MA}_{\aleph_1} and the imported theorem at full strength.
  • S3: refutation-failed, under the same conditions; the consistency step rests on Theorem C.
  • S4: refutation-failed, under the same conditions.
  • S5: refutation-failed, under the hypothesis it names.
  • S6: refutation-failed.
  • S7: refutation-failed, resting on Folkman's Theorem 1 (held, statement checked on the page image) and the Nešetřil--Rödl theorem (second-hand).
  • S8: refutation-failed.
  • S9: refutation-failed under the route reading; the literal reading is not established (F4).
  • S10: refutation-failed, with the imported negative relation's hypothesis left open as the section leaves it.
  • S11: refutation-failed as a statement about the held corpus.
  • S12(a): refutation-failed. S12(b): proof defective; statement unresolved (F1).
  • S13: refutation-failed for the consistency reading; the word "refutes" overstates it (F2).
  • S14: not a claim; F3 and F5 record the fidelity corrections, and the lead's reference to the first section's CH obstruction was not assessed.

Limitations: the chapter of Baumgartner (1989) and the paper of Nešetřil and Rödl are not held, and the catalog page for Problem 597 was not consulted, so the three catalog attributions in the section's first paragraph and the full-strength statement of the imported theorem are taken at the standing their library pages record. The first section of the connections page, which the lead cites for a CH obstruction, is outside this review's read set. This focused review assigns no tier and changes no status.