{"id":"34904e51-bae7-4704-8614-9f8a30559b81","arxiv_id":"2505.00505","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":8.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":0,"one_line_summary":"Every generically trivial torsor under a smooth group scheme over a smooth variety over any field is Zariski semilocally trivial, settling the Grothendieck-Serre question.","lead":"This paper proves the Grothendieck-Serre conjecture in full generality: over any base field, every generically trivial torsor under a smooth algebraic group trivializes Zariski semilocally. It builds new purity and extension theorems for group schemes that only exist over imperfect fields, such as wound unipotent groups and pseudo-abelian varieties.","discovery_kind":"first_principles","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Lemma 8.1.1's proof is truncated and the paper concedes it is known only for reductive G; this unverified bridge is the most load-bearing step for Theorem 1.1.1.","rationale":"The reader's weakest assumption identifies Lemma 8.1.1 as load-bearing, and the manuscript itself supports this: Section 8.1 states the lemma and immediately truncates with the admission that the argument appears in the literature only for reductive G. The main theorem's reduction to the relative P^1 statement Theorem 7.2.1 depends directly on this lemma. The quoted inputs [CP16, Theorem 5.1.3] and [CGP15, Theorem C.2.30] are deep but are part of the published record; the missing proof of Lemma 8.1.1 is not. Nothing in the visible text contradicts the main theorem, and the visible Sections 1–7 are internally coherent and consistent with known results, so a rejection is not warranted. A conditional accept with the condition that the full proof of Lemma 8.1.1 be supplied and verified is the appropriate outcome. My check does not change the reader's verdict; it sharpens the reason for it.","tokens_in":65111,"tokens_out":12421,"duration_ms":131462,"concrete_test":"Obtain the complete proof of Lemma 8.1.1 from the authors and re-derive it in the minimal non-reductive cases: (i) G a smooth wound unipotent k-group over an imperfect field, e.g., a group defined by a p-polynomial with nonzero principal part as in §2.7.1, and (ii) G = Res_{k'/k}(A) for a purely inseparable k'/k and an abelian variety A over k'. In each case, check every step of the geometric reduction (spreading out, patching over P^1_R, excision of Z) and identify where reductivity was used in the reductive proof. If the construction of Z requires G/P to be proper or the affine Grassmannian of G to be ind-quasi-compact, rather than only pseudo-proper or pseudo-complete, then Lemma 8.1.1 is unsupported for non-reductive G and the proof of the main theorem has a gap.","verdict_should_be":"UNCHANGED","load_bearing_attack":"Theorem 1.1.1 is proved by combining Theorem 7.2.1 with Lemma 8.1.1. Lemma 8.1.1 asserts that any generically trivial G-torsor over a geometrically regular semilocal k-algebra R (G locally of finite type) can be realized as the t=0 fiber of a G-torsor over P^1_R that is trivial away from an R-finite closed Z ⊂ A^1_R. The visible text of §8.1 stops immediately after the sentence 'The argument is standard but appears in the literature only for reductive G'. The standard geometric reduction in [FP15]/[Pan20a] is written for reductive group schemes and uses reductive-specific inputs; the needed generalization to arbitrary smooth (or locally finite type with the torus condition) k-group schemes, including wound unipotent groups and pseudo-abelian varieties over imperfect k, is not shown in the reviewed text. If Lemma 8.1.1 fails for some non-reductive smooth G, then Theorem 1.1.1 does not follow. The additional deep quoted inputs in Theorem 7.2.1 ([CP16, Theorem 5.1.3], [CGP15, Theorem C.2.30], Proposition 7.1.6) are located in published sources and can be checked; the missing proof of Lemma 8.1.1 cannot. Thus the central claim currently rests on an unverified bridge that the paper itself flags as nonstandard beyond the reductive case.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper claims a complete resolution of the Grothendieck–Serre question over an arbitrary base field. For a field k, a geometrically regular semilocal k-algebra R with fraction field K, and a smooth k-group scheme G (or, more generally, a locally finite type k-group scheme satisfying the torus condition of Remark 2.2.13), it asserts that every generically trivial G-torsor over R is trivial: the kernel of H^1(R,G) -> H^1(K,G) is a singleton. The proof is organized through a sequence of independent results: purity theorems for torsors under pseudo-finite, pseudo-proper, and pseudo-complete groups; an Auslander–Buchsbaum type extension theorem for quasi-reductive groups; a classification of G-torsors over P^1_k; Birkhoff, Cartan, and Iwasawa decompositions; and a sectionwise triviality theorem for torsors over relative P^1_A. The final step is stated to follow by combining Lemma 8.1.1 with Theorem 7.2.1.","tokens_in":65288,"tokens_out":7958,"duration_ms":84200,"significance":"If correct, the main theorem settles a long-standing question in the full stated generality and introduces a substantial toolkit of new structural notions, including pseudo-properness, pseudo-finiteness, and refined purity statements that are of independent interest. The paper is careful with hypotheses, gives counterexamples showing optimality of its assumptions, and systematically reduces to classical cases such as finite groups, abelian varieties, and reductive groups. These are real strengths. However, the proof of Lemma 8.1.1, which is the bridge from generically trivial torsors over a semilocal ring to torsors over a relative P^1, is not present in the reviewed text; the manuscript itself flags that the argument is nonstandard beyond the reductive case. The central theorem is therefore not fully verifiable from the visible text. If the missing proof is supplied and is correct, this appears to be a top-tier contribution.","major_comments":[{"comment":"The proof of Lemma 8.1.1 is not included in the reviewed text: after the sentence 'The argument is standard but appears in the literature only for reductive G', the presentation stops. This lemma is load-bearing because Theorem 1.1.1 (Theorem 8.1.2) is obtained by combining Lemma 8.1.1 with Theorem 7.2.1. The standard geometric reductions in [FP15] and [Pan20a] are written for reductive group schemes and use reductive-specific ingredients, so the assertion of Lemma 8.1.1 for arbitrary locally finite type k-group schemes, including non-reductive smooth groups, is not something a reader can check from the visible text. The authors should supply the full proof and explain explicitly which reductive-specific inputs are replaced, and how the torus condition in the statement of Theorem 1.1.1 is used in the geometric reduction.","section":"§8.1, Lemma 8.1.1"},{"comment":"At the end of the proof of Theorem 7.2.1, the argument reduces to the case of a quasi-semisimple, simply connected k-group and then invokes 'the deformation-theoretic [ČF23, Proposition 3.1] implies that E is constant.' The cited statement was originally developed for reductive groups, and the whole point of the present paper is to go beyond the reductive case. The manuscript needs to state the precise version of [ČF23, Proposition 3.1] that is being used for quasi-semisimple groups, or explain why the reductive proof carries over verbatim. Without this, the final bootstrap step of the sectionwise triviality theorem has a gap that is not covered by the other cited references.","section":"§7.2, proof of Theorem 7.2.1"},{"comment":"Theorem 1.1.1 combines Lemma 8.1.1 with Theorem 7.2.1, but Theorem 7.2.1 itself rests on several deep quoted inputs: [CP16, Theorem 5.1.3] on simply connected covers of quasi-semisimple groups, [CGP15, Theorem C.2.30] on split reductive subgroups, and Proposition 7.1.6 on unramifiedness of the Whitehead group. These are published results and can be checked, but the manuscript should clearly state which of them are being invoked outside the reductive setting and whether any part of their proof is being adapted rather than quoted. The current text says Theorem 7.2.1 is 'the most technically demanding part of the proof,' so the reader needs precise hypotheses for each quoted input.","section":"§8.1 and §7.2, dependency structure"}],"minor_comments":[{"comment":"The table of contents lists sections 1.1–1.5 and then jumps to section 2, but the body contains sections 1.6 ('Fixed base field') and 1.7 ('Notation and conventions'). Please renumber or update the table of contents.","section":"Table of contents and §1.6"},{"comment":"The term 'cckp kernel' is used without expansion. Please define it or give the full phrase at first use, since it is not a standard acronym for all readers.","section":"§2.1.2(7)"},{"comment":"In the proof of Theorem 4.3.1(ii), the sentence 'By Lemma 4.1.1, we may assume that ℓ = k' is not immediate, because G is a Weil restriction. Please clarify the base-change or descent step that justifies this reduction.","section":"§4.3.1(ii), proof"},{"comment":"In the iteration 'we replace G by D(G), then D(G) by D(G)_tor, then D(G)_tor by D(D(G)_tor), and so on', the termination of the process is asserted but not justified. Since the dimensions strictly decrease unless the group is perfect, a one-sentence explanation would remove a small gap.","section":"§7.2, proof of Theorem 7.2.1"}],"recommendation":"major_revision","confidential_remarks":"The reviewed text appears to stop in the middle of the proof of Lemma 8.1.1. If this is a truncation of the submitted manuscript rather than the full version sent to referees, please ensure that the complete proof is made available. The rest of the paper is substantial and promising, but the missing geometric reduction must be verifiable before the main theorem can be accepted."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"You should know this is the real thing: it settles the Grothendieck–Serre question for smooth k-group schemes over arbitrary base fields, and the body of the paper is as careful as you would expect from these authors. The novelty is genuine: the known cases (perfect k, reductive G, affine G over kJtK) are properly surveyed, and the new cases—arbitrary smooth G over imperfect k, including wound unipotent groups, pseudo-abelian varieties, and quasi-reductive groups—are exactly the hard ones that were open. The paper earns its length. It develops a full structure theory for k-group schemes locally of finite type, proves new purity theorems for pseudo-finite, pseudo-proper, and pseudo-complete groups, and derives the Auslander–Buchsbaum extension theorem, the P^1 classification, and the Birkhoff/Cartan/Iwasawa decompositions. The examples in Section 8.2 are used honestly to show the hypotheses are optimal, not to dodge difficulties. The visible text is internally coherent, with explicit hypotheses and no sign of circularity. The reliance on the authors' earlier work is heavy, but those are published sources and the new affineness result (Proposition 2.3.5) is clearly flagged as new.\n\nThe soft spot is exactly where the reader's stress test lands. Lemma 8.1.1 is the bridge from the P^1 results to the main theorem, and its proof is not in the reviewed text: the paper says the argument is standard but appears in the literature only for reductive G, and then the copy truncates. For arbitrary locally finite type G, including the non-reductive cases specific to imperfect fields, that generalization is load-bearing. I do not read this as a red flag—the rest of the paper is too careful, and the statement is plausible—but it is a real unverified step. Theorem 7.2.1 also quotes deep structural inputs from [CP16] and [CGP15]; those are published and checkable, but they need an expert's eye in exactly the imperfect-field edge cases.\n\nWho is this for? Arithmetic geometers working on torsors, purity, and the structure theory of pseudo-reductive and quasi-reductive groups. It deserves a serious referee: an editor should send it to someone who knows that literature cold, with a specific request to verify Lemma 8.1.1 and the quoted inputs in Sections 7 and 8. If those check out, this is a landmark. My recommendation: engage with it, but require the missing proof to be supplied or replaced by a precise reference before accepting.","headline":"A major, credible resolution of the Grothendieck–Serre question over imperfect fields; the only real soft spot is the last-mile geometric reduction lemma whose proof is not visible in the review copy.","tokens_in":65992,"tokens_out":1920,"would_cite":true,"duration_ms":21621,"reading_group":"yes","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":["14L10","14L30","14M17","14G17","20G10"],"pacs":[],"model":"deepseek-v4-flash","headline":"Proved: generically trivial torsors trivialize over every base field.","keywords":["Grothendieck–Serre conjecture","generically trivial torsors","pseudo-reductive groups","quasi-reductive groups","wound unipotent groups","pseudo-abelian varieties","imperfect fields","Whitehead group"],"falsifier":"Take an imperfect field $k$ of characteristic $p$ and a wound unipotent $k$-group $G$ presented as the vanishing locus of a $p$-polynomial $F$ whose principal part has no nontrivial $k$-zeros, so that $H^1(R,G)=R/F(R^{N+1})$ for affine $R$ by (2.7.1.1), and compute the Čech class of $1/(xy)$ on $\\mathbb{A}^2_k\\setminus\\{(0,0)\\}$. The purity theorem 1.2.2(iii) predicts this class is zero; a nonzero value — for instance for $G=\\mathrm{Res}_{k'/k}\\mathbb{G}_m/\\mathbb{G}_m$ or one of the minimal wound groups of Lemma 2.7.2 — would be a direct counterexample to the central claim, and the computation is explicit enough to run in practice.","tokens_in":64788,"feed_emoji":"📐","tokens_out":26258,"duration_ms":233500,"temperature":0.7,"pith_summary":"The paper sets out to settle the Grothendieck–Serre question, posed by Grothendieck and Serre in 1958: for a smooth group scheme $G$ and a smooth variety $X$ over a field $k$, is every $G$-torsor over $X$ that becomes trivial at the generic point necessarily trivial in a Zariski neighborhood of each point? The conclusion was known for reductive $G$ and for perfect $k$; the open territory was imperfect fields, where non-smooth and non-reductive group schemes — wound unipotent, pseudo-reductive, quasi-reductive, pseudo-abelian — appear inevitably. The paper proves the full statement for every base field: for geometrically regular semilocal $k$-algebras, the map $H^1(R,G)\\to H^1(K,G)$ on torsor classes has trivial kernel. A sympathetic reader should care because the paper's corollaries are concrete: purity and extension theorems for torsors in dimension two, a classification of torsors over $\\mathbb{P}^1_k$, Birkhoff–Cartan–Iwasawa decompositions over $k((t))$, and the principle that torsors over $\\mathbb{P}^1_A$ which trivialize at one section trivialize at all sections, which is the engine behind the main theorem.","feed_headline":"Proved: generically trivial torsors trivialize over every base field","feed_subtitle":"New purity and decomposition methods close the imperfect-field cases of the 1958 Grothendieck–Serre prediction.","key_machinery":"The carrier of the argument is a structural 'fundamental filtration' of an arbitrary $k$-group scheme locally of finite type, a chain of closed normal subgroups whose successive subquotients are tame: étale, pseudo-finite (only finitely many $k_s$-points; e.g., kernels of the comparison maps), pseudo-abelian varieties (smooth, connected, with no nontrivial smooth connected affine subgroup), wound unipotent groups, and quasi-reductive groups (connected, smooth, affine, with no nontrivial split unipotent normal $k$-subgroup, a class containing both reductive groups and wound unipotent groups). The decisive device is the comparison map $i_G\\colon G\\to \\mathrm{Res}_{k'/k}(\\overline{G})$ sending a pseudo-reductive group or pseudo-abelian variety to the restriction of scalars of its reductive or abelian quotient along the purely inseparable field of definition of the geometric unipotent radical; the paper proves the cokernel is affine (Proposition 2.3.5) and the kernel is pseudo-finite unipotent, so torsor problems can be pushed to reductive or abelian ones. On the geometric side, new purity theorems show that torsors under pseudo-finite, pseudo-proper, and pseudo-complete groups extend uniquely across closed subsets of codimension $\\geq 2$, yielding an Auslander–Buchsbaum-type extension theorem for torsors under quasi-reductive groups over 2-dimensional geometrically regular schemes. The final input is the unramifiedness of the Whitehead group $W(K,G)=G(K)/G(K)^+$ for quasi-semisimple, simply connected $G$, which controls how arbitrary torsor patchings along closed subschemes of $\\mathbb{G}_{m,A}$ differ from elementary ones and yields the sectionwise triviality theorem for torsors over $\\mathbb{P}^1_A$.","core_discovery":"The paper's central claim is that the Grothendieck–Serre prediction holds in full: for a field $k$, a locally finite type $k$-group scheme $G$ whose every $k$-torus lies in its largest smooth $k$-subgroup (automatic when $G$ is smooth), and a geometrically regular semilocal $k$-algebra $R$ with $K=\\mathrm{Frac}(R)$, every $G$-torsor over $R$ that trivializes over $K$ is already trivial, so $\\mathrm{Ker}(H^1(R,G)\\to H^1(K,G))$ is a singleton. For a smooth $k$-variety $X$, this means every generically trivial $G$-torsor over $X$ trivializes Zariski semilocally on $X$. The route passes through a chain of new statements, each of independent interest: purity for torsors under pseudo-finite, pseudo-proper, and pseudo-complete $k$-groups; an Auslander–Buchsbaum extension theorem for torsors under quasi-reductive $k$-groups (for instance, wound unipotent $G$-torsors over $\\mathbb{A}^2_k\\setminus\\{(0,0)\\}$ extend over $\\mathbb{A}^2_k$, the opposite of what happens for $\\mathbb{G}_a$); a classification of $G$-torsors over $\\mathbb{P}^1_k$; Birkhoff, Cartan, and Iwasawa decompositions for $G(k((t)))$; and a sectionwise triviality theorem for torsors over the relative $\\mathbb{P}^1_A$ that is the technical heart of the proof.","pith_inferences":["If the main theorem is right, the natural next question is the optimal base-change version: for a smooth group scheme defined directly over a regular semilocal ring $R$ rather than descended to $k$, the Grothendieck–Serre conclusion is known for reductive groups and fails beyond them (the paper's Examples 8.2.1–8.2.2); the structure here suggests a fiberwise torus condition as the right hypothesis","The purity theorem for wound unipotent groups has no perfect-field analogue, so it invites a direct geometric test: the affine Grassmannian of a quasi-reductive group should be ind-pseudo-proper, a route the paper mentions as an alternative to its Birkhoff–Cartan arguments; establishing that would remove some of the heavy structural inputs from the loop-group proofs.","Because essentially any group scheme arises as the automorphism group of a projective variety, the theorem implies that forms of such varieties over regular semilocal bases are governed by the same torsor triviality; a concrete check is to take a variety whose automorphism group is a wound unipotent group over an imperfect field and verify that no new forms appear over $\\mathbb{A}^2_k\\setminus\\{(0"],"forward_implications":["For a smooth $k$-group $G$ and a smooth $k$-variety $X$, every generically trivial $G$-torsor over $X$ trivializes after restriction to the semilocal ring of any finite set of points of $X$, in particular at every Zariski local ring.","Purity: torsors under wound unipotent groups over $\\mathbb{A}^2_k\\setminus\\{(0,0)\\}$ extend uniquely to torsors over $\\mathbb{A}^2_k$, and more generally, under the paper's hypotheses, torsors under quasi-reductive groups extend across height-2 points of 2-dimensional geometrically regular $k$-schemes; this is the opposite of the $\\mathbb{G}_a$ case, where the punctured plane's non-affineness is d","For a quasi-reductive $G$, $G$-torsors over $\\mathbb{P}^1_k$ are classified by $H^1(B\\mathbb{G}_m,G)$; the Zariski locally trivial ones are indexed by cocharacters $\\mathbb{G}_m\\to G$ up to $G(k)$-conjugation, and a torsor trivial at one $k$-point is trivial at every $k$-point and Zariski locally trivial.","Over $k((t))$, a group $G$ whose largest connected smooth affine subgroup is quasi-reductive admits Birkhoff, Cartan, and Iwasawa decompositions, e.g. $G(k((t)))=\\bigsqcup_\\lambda G(k[t^{-1}])\\,t^\\lambda\\,G(k[[t]])$; in particular, whenever $G_\\kappa$ has no nontrivial split $\\kappa$-torus, every $K$-point of $G$ extends to an $O$-point for every discrete valuation ring $O$ over $k$ with residue f","For a smooth $G$ and a semilocal $k$-algebra $A$, a $G$-torsor over $\\mathbb{P}^1_A$ trivial at $t=\\infty$ is trivial at $t=0$; consequently $H^1(A,G)$ injects into $H^1(A((t)),G)$, so no nontrivial torsor over $A$ becomes trivial after passing to the Laurent series ring."],"supporting_citations":[{"why":"Established the algebraically closed field case and several special cases of the Grothendieck–Serre prediction; the baseline theorem and reduction strategy this paper extends.","marker":"[CTO92]"},{"why":"The reductive-group case over arbitrary infinite base fields, whose relative P^1 approach Theorem 7.2.1 extends and whose geometric reduction underlies Lemma 8.1.1.","marker":"[FP15]"},{"why":"Supplies the structure theory of pseudo-reductive groups used throughout: comparison map, pseudo-parabolic subgroups, Levi subgroups, and the Appendix C inputs (including Theorem C.2.30) on which Proposition 7.1.6 rests.","marker":"[CGP15]"},{"why":"Supplies the simply connected cover of quasi-semisimple groups (Theorem 5.1.3), the key reduction step in Theorem 7.2.1.","marker":"[CP16]"},{"why":"Introduced pseudo-abelian varieties and proved their structure theorem; used for the pseudo-abelian case of purity and for the pseudo-finite covers of Ga used in counterexamples.","marker":"[Tot13]"},{"why":"The geometric approach to Grothendieck–Serre for reductive groups via torsors over P^1_A; Theorem 7.2.1 extends its Theorem 3.5, and its Proposition 3.1 supplies the final deformation-theoretic step.","marker":"[ČF23]"},{"why":"The Gabber–Quillen geometric presentation theorem, used in the purity proofs to reduce to power-series rings (Lemma 4.2.2(b), Theorem 4.3.1(i)).","marker":"[CTHK97]"},{"why":"Classification of G-torsors over [A^n/G_m], the key input for the P^1 classification (Theorem 5.2.4) and the Cartan decomposition argument (Lemma 6.2.1).","marker":"[Wed24]"},{"why":"Its Lemma 2.1 on affineness of such quotient groups is the basis of the new affineness Proposition 2.3.5; its torus purity is used in Theorem 4.3.1(ii).","marker":"[Čes19]"},{"why":"The patching theorem for torsors on P^1, used to pass between double cosets of loop groups and torsor classes in the Birkhoff/Cartan arguments and Theorem 5.2.4.","marker":"[MB96]"}],"fun_headline_variants":["Grothendieck–Serre proven for every base field, perfect or not","Imperfect fields no longer exceptional: torsor triviality solved","Full Grothendieck–Serre: generically trivial torsors trivialize","New purity and decomposition tools close the imperfect-field cases","From reductive to all smooth groups: Grothendieck–Serre settled"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The whole proof leans on a geometric reduction step (Lemma 8.1.1) that turns a generically trivial $G$-torsor over a semilocal ring $R$ into a $G$-torsor over $\\mathbb{P}^1_R$ that is trivial away from an $R$-finite closed set with prescribed behavior at $t=0$; the paper notes this step exists in the literature only for reductive $G$, so its validity for arbitrary locally finite type group schemes, together with the deep structural theorems it invokes from the pseudo-reductive theory, is the assumption on which everything rests.","fun_headline_variants_meta":{"raw":{"variants":["Grothendieck–Serre proven for every base field, perfect or not","Imperfect fields no longer exceptional: torsor triviality solved","Full Grothendieck–Serre: generically trivial torsors trivialize","New purity and decomposition tools close the imperfect-field cases","From reductive to all smooth groups: Grothendieck–Serre settled"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000258,"raw_usage":{"total_tokens":1789,"prompt_tokens":1356,"completion_tokens":433,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":972,"completion_tokens_details":{"reasoning_tokens":337}},"tokens_in":972,"tokens_out":433,"duration_ms":4846,"temperature":1.0,"reasoning_tokens":337,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-16T04:41:11.442969+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Take an imperfect field $k$ of characteristic $p$ and a wound unipotent $k$-group $G$ presented as the vanishing locus of a $p$-polynomial $F$ whose principal part has no nontrivial $k$-zeros, so that $H^1(R,G)=R/F(R^{N+1})$ for affine $R$ by (2.7.1.1), and compute the Čech class of $1/(xy)$ on $\\mathbb{A}^2_k\\setminus\\{(0,0)\\}$. The purity theorem 1.2.2(iii) predicts this class is zero; a nonzero value — for instance for $G=\\mathrm{Res}_{k'/k}\\mathbb{G}_m/\\mathbb{G}_m$ or one of the minimal wound groups of Lemma 2.7.2 — would be a direct counterexample to the central claim, and the computation is explicit enough to run in practice.","supporting_citations":[],"review_version":1}