Pith. sign in

REVIEW 4 minor 2 cited by

The quantum spin Brauer category

T0 review · 0 major / 4 minor · reviewed 2026-08-16 · deepseek-v4-flash

Pith's one-line read The quantum spin Brauer category is a diagrammatic braided monoidal category whose incarnation functor to finite-dimensional type-1 modules of $U_q(\mathfrak{so}(N))$ or $U_q(\mathfrak{o}(N))$ is full and becomes essentially surjective…

desk verdict A genuinely new diagrammatic category that resolves the missing spin module in the Kauffman setting; the main theorems are as advertised under the stated generic-q assumption. read the letter →

arxiv 2504.16618 v1 pith:WPJIZ6TD submitted 2025-04-23 math.QA math.RT

classification math.QAmath.RT MSC 18M1518M3017B37
keywords quantumspinBrauercategoryKauffmanquantizedenvelopingalgebramoduleCliffordKaroubienvelopeinterpolatingSchur–Weylduality
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper introduces the quantum spin Brauer category, a diagrammatic braided monoidal category with one generating strand for the quantum natural module $V$ and one for the quantum spin module $S$. The authors prove that the natural incarnation functor from this category to finite-dimensional type-1 modules of $U_q(\mathfrak{so}(N))$ for odd $N$, or $U_q(\mathfrak{o}(N))$ for even $N$, is full and becomes essentially surjective after passing to the idempotent completion. Restricting to the subcategory obtained by omitting the two spin-spin braidings, the kernel of the induced functor is exactly the tensor ideal of negligible morphisms, so its semisimplification is equivalent to $U_q(N)\text{-mod}$. If the paper is right, quantum orthogonal representation theory, including spin modules that the Kauffman category misses, has a simple diagrammatic interpolating category.

What carries the argument

The load-bearing object is the quantum spin module $S$, constructed as a module for the quantum Clifford algebra $\mathrm{Cl}_q(N)$; Clifford multiplication provides the generating morphism $V\otimes S\to S$. The category $\mathrm{QSB}(N)$ is the Kauffman category enlarged by this self-dual object $S$, with parameters specialized so that quantum dimensions match. Fullness is carried by one operator $B_N\in \mathrm{Cl}_q(N)\otimes \mathrm{Cl}_q(N)$, whose action on $S\otimes S$ has pairwise distinct eigenvalues on the simple summands; the 'barbell' diagrams built from $B_N$ therefore generate all endomorphisms of $S^{\otimes r}$. Essential surjectivity then uses semisimplicity of $U_q(N)\text{-mod}$ and finite-dimensionality of the relevant morphism spaces in the subcategory $\mathrm{QSB}'$ to lift idempotents from modules back to diagrams.

What would settle it

Specialize to a root of unity, say $q$ a primitive $m$-th root with $m\ge 3$, and compare dimensions of morphism spaces in $\mathrm{QSB}'$ with corresponding $\operatorname{Hom}$ spaces in $U_q(N)\text{-mod}$ for small $r,s$; a mismatch would falsify fullness, and a simple module whose projecting idempotent cannot be lifted to a diagram would falsify essential surjectivity. At $q=1$, the comparison should reproduce the spin Brauer category results.

Watch

Extended reading notes

Core claim

The paper's central claim is that quantum orthogonal spin representations admit a diagrammatic interpolating category. Concretely, the incarnation functor $F:\mathrm{QSB}(N)\to U_q(N)\text{-mod}$ of Theorem 6.1 is full (Theorem 7.10), and its extension to the additive Karoubi envelope is essentially surjective (Theorem 8.5). Restricting to the subcategory $\mathrm{QSB}'$ obtained by omitting the two spin-spin braiding morphisms, the kernel of the induced functor coincides with the tensor ideal of negligible morphisms, so the semisimplification of $\mathrm{Kar}(\mathrm{QSB}')$ is equivalent to $U_q(N)\text{-mod}$ (Theorem 8.7). In concrete terms, every finite-dimensional type-1 module of $U_q(\mathfrak{so}(N))$ (odd $N$) or $U_q(\mathfrak{o}(N))$ (even $N$) is a direct summand of some $V^{\otimes r}\otimes S^{\otimes s}$, with the idempotent projecting onto it represented by a diagram.

Load-bearing premise

The argument assumes $q$ is not a root of unity, so $U_q(N)\text{-mod}$ is semisimple; at roots of unity the idempotent-lifting and eigenvalue arguments that make the functor essentially surjective would not go through.

Editorial extensions

If this is right

  • Every type-1 simple $U_q(N)$-module is a summand of $V^{\otimes r}\otimes S^{\otimes s}$ for some $r,s$, and the projecting idempotent is represented by a diagram in $\mathrm{QSB}'$.
  • All endomorphisms of $S^{\otimes r}$ are generated by barbell diagrams, so the centralizer algebras of spin tensor powers are diagrammatic.
  • The semisimplification of $\mathrm{Kar}(\mathrm{QSB}')$ is equivalent to $U_q(N)\text{-mod}$, making $\mathrm{QSB}'$ an interpolating category for quantum orthogonal representations.
  • For even $N$, the target is $U_q(\mathfrak{so}(N))\rtimes\mathbb{Z}/2\mathbb{Z}$, so the construction covers the pin-type single spin module rather than two separate spin modules.
  • Applying the standard affinization procedure to this braided category gives a quantum affine spin Brauer category acting on translation functors by tensoring with $S$ and $V$.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • If the equivalence holds at generic $q$, specializing to $q=1$ should recover the non-quantum spin Brauer category results, giving a checkable consistency condition.
  • The same diagrams could produce quantum invariants of links and tangles colored by spin modules, extending the invariants already associated with the Kauffman category.
  • At roots of unity the semisimplicity premise fails, so the Karoubi-envelope statement is not expected to survive; a modified statement would likely need non-semisimple idempotent lifting or a different completion.
  • The explicit description of the kernel as negligible morphisms suggests a combinatorial characterization of negligible diagrams, which may connect to the web-based presentations of orthogonal quantum groups.
Share X Bluesky LinkedIn Reddit HN

Signed reviews

No signed human review yet.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

0 major / 4 minor

Summary. The paper introduces a strict pivotal braided monoidal category QSB(q,t,κ,d_S), the quantum spin Brauer category, with two generating objects V and S subject to diagrammatic relations that enlarge the Kauffman category by a formal spin object. For the specific parameter values in (6.2), the authors construct the incarnation functor F: QSB(N) → U_q(N)-mod sending V and S to the quantum natural and spin modules (Theorem 6.1). They prove that F is full (Theorem 7.10) and that, after passing to the additive Karoubi envelope, it is essentially surjective (Theorem 8.5). For the subcategory QSB′ obtained by omitting the braidings on two copies of S, the kernel of the induced functor is shown to be exactly the tensor ideal of negligible morphisms, so the semisimplification of Kar(QSB′) is equivalent to U_q(N)-mod (Theorem 8.7). The main technical ingredients are the quantum antisymmetrizer construction of Section 3, the quantum Clifford algebra and spin module of Section 5, eigenvalue computations for the operator B_N in Section 7, and finite-dimensionality results for Hom spaces in QSB′ in Section 8.

Significance. This is a substantial contribution to the diagrammatic categorification of orthogonal and spin quantum group representations. If the main theorems are correct, the paper provides a comparatively simple braided monoidal category that interpolates the finite-dimensional type-1 module categories of U_q(so(N)) and U_q(o(N)), complementing the more elaborate web categories in the literature. The construction is concrete: the parameter specializations in (6.2) are explicit, the functor to U_q(N)-mod is defined by exact formulas, and the proof of Proposition 5.6 is carried out in full detail in Appendix A. The paper also benefits from being honest about its limitations, notably that the kernel of F on the full category QSB is not described and that the semisimplification theorem concerns the subcategory QSB′. The main structural dependency, semisimplicity of U_q(N)-mod for generic q, is explicitly stated and standard. Overall, the central claims are internally consistent under the stated generic-q assumptions.

minor comments (4)
  1. [§7, Theorem 7.10] The proof of fullness is considerably more compressed than the rest of the paper: it says the proof is analogous to [MS24, Th. 7.9] and only displays the changed diagrammatic computation, without explicitly identifying the diagram denoted D or the inductive statement being adapted. Since this is a central theorem, please spell out the structure of the induction or quote the precise facts from [MS24] that are being used, and identify the replaced diagram explicitly.
  2. [§8, Theorem 8.5] The idempotent lifting step ('Hence, we can lift e_M to an idempotent e') is asserted without justification. This is a standard fact: because End_QSB′(V^r⊗S^s) is finite-dimensional by Proposition 8.3 and the target is semisimple, the radical of the source maps to zero and idempotents lift through nilpotent ideals. Please include this argument or a reference so that the proof is self-contained.
  3. [§8, Theorem 8.5] The statement that every simple U_q(N)-module M appears as a summand of V^r⊗S^s, with s = 0 or 1 according to the integrality of the highest weight, is used essentially in the proof of essential surjectivity but is neither proved nor cited. It is standard, but a reference or a one-sentence justification would make the argument complete.
  4. [§6, Eq. (6.2)] The sign σ_N in the definition of d_S implies that the loop value for the spin object can be negative; for example, when N = 3 one obtains d_S = -(q^{1/2}+q^{-1/2}). This is compatible with the chosen pivotal structure, but a remark noting that d_S is a categorical dimension rather than the classical dimension of the spin module would help readers.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the fullness and essential-surjectivity theorems are derived from the category's relations and standard representation theory, not from fitted outputs or self-referential uniqueness claims.

full rationale

The paper's construction is a presentation: the category QSB is defined by generators and relations with parameters, and then the parameters are specialized in (6.2) to match known quantum dimensions and R-matrix scalars. The incarnation functor F is defined and shown to respect the relations in Theorem 6.1. This is not circular: the relations are inputs, and fullness (Theorem 7.10) is a nontrivial statement that the diagrammatic endomorphism algebras surject onto the module-theoretic ones. The proof of fullness uses the barbell operator B_N; its eigenvalues on the simple summands of S⊗S are derived in Propositions 7.4 and 7.6 from the category's own trace relations (3.25) and (3.26), together with standard quantum dimension formulas. Thus the eigenvalue data is a consequence of the diagrammatic relations, not an input fitted to the module category. Essential surjectivity (Theorem 8.5) uses semisimplicity of U_q(N)-mod (Proposition 4.4) and the standard fact that every simple module appears in some V^⊗r⊗S^⊗s with s = 0 or 1; the idempotent lift is justified by finite dimensionality (Proposition 8.3) and the surjectivity established by fullness. Theorem 8.7 identifies the kernel with the negligible ideal via a general categorical lemma [SW24, Prop. 6.9] once fullness, essential surjectivity, and Proposition 8.2 are established; this lemma is parameter-free and does not encode the target category's specific structure. Self-citations to [MS24] supply proof templates and non-quantum analogues, but the load-bearing computations and structural arguments are either proved in the text or rest on standard, externally verifiable facts. No fitted parameter is renamed as a prediction, and no defining relation is equivalent to the theorem it supports.

Assumptions & free parameters 3 free parameters · 5 assumptions · 1 invented entities

The central construction introduces a formal category with parameters (q,t,kappa,d_S) and then specializes them in (6.2) to match the known representation theory. The free parameters listed are those specializations; they are not fitted to data but chosen to make the functor well-defined. The axioms are standard facts in quantum group representation theory plus the explicit non-root-of-unity assumption. The only new entity is the formal generating object S, which is anchored by an actual spin module in U_q(N)-mod, so it carries independent evidence.

free parameters (3)
  • kappa = (-1)^(nN) q^((1-N)/2)
    Specialized in (6.2) so that the mixed trivalent vertex V tensor S to S has the correct scalar and d_V becomes [N-1]+1. This is a parameter of the formal category QSB(q,t,kappa,d_S), not fitted to experimental data.
  • t = q^(N(1-N)/8)
    Chosen in (6.2) so that the S tensor S cap satisfies the relation (2.4) with scalar t. Determined by the braiding eigenvalue on the spin module.
  • d_S = sigma_N * prod_{i=1}^n (q^(N/2-i)+q^(i-N/2))
    Set to the quantum dimension of the spin module so that the cap on S maps to the invariant form. A formal parameter in Def. 2.1; fixed in (6.2).
assumptions (5)
  • domain assumption q is not a root of unity
    Assumed in Sections 3 and 8 to ensure quantum integers are nonzero and eigenvalues of B_N are distinct (see (3.1) and the preamble to Section 3).
  • domain assumption q^(2r-1)*kappa^2 + 1 is nonzero for all r in N
    Equation (3.1) is used to prove the quantum antisymmetrizer relations; at the specialization (6.2) it becomes q^(2r-N)+1, which is nonzero for transcendental q.
  • standard math U_q(N)-mod is semisimple
    Proposition 4.4; known for generic q in types B and D. Used in Prop. 4.6, Thm. 7.9, Thm. 8.5, and Thm. 8.7.
  • standard math The braiding on U_q(so(N))-mod extends to U_q(N)-modules
    Proposition 4.6, proof uses [KS97, Prop. 8.22] and [DF94, Prop. 2.3.3]; needed for the functor to respect relations (2.1) and (2.5).
  • standard math Quantum Clifford algebra presentation of Ding-Frenkel and Hayashi
    Section 5 relies on [DF94] for the relations (5.1) and on [Hay90] for the algebra homomorphism in Proposition 5.5; Proposition 5.3 proves the isomorphism Cl_q(N) isomorphic to Cl(N).
invented entities (1)
  • Generating object S in QSB (formal quantum spin module) independent evidence
    purpose: Adds a second generating object to the Kauffman category corresponding to the quantum spin module of U_q(N); this is the key enlargement that makes the functor essentially surjective.
    The incarnation functor F maps S to the actual spin module constructed in Section 5.3, and the quantum dimension d_S matches the known formula (6.2). So the formal object has a concrete target outside the diagrammatic category.

how reviews work

0 comments
Cite this review

Pith. "Pith review of The quantum spin Brauer category." pith.science (2026). https://pith.science/paper/WPJIZ6TD

@misc{pith2026250416618,
  author       = {Pith},
  title        = {Pith review of: The quantum spin Brauer category},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/WPJIZ6TD}},
  note         = {Machine review of arXiv:2504.16618}
}
abstract

We introduce a diagrammatic braided monoidal category, the quantum spin Brauer category, together with a full functor to the category of finite-dimensional, type $1$ modules for $U_q(\mathfrak{so}(N))$ or $U_q(\mathfrak{o}(N))$. This functor becomes essentially surjective after passing to the idempotent completion. The quantum spin Brauer category can be thought of as a quantum version of the spin Brauer category introduced previously by the authors. Alternatively, it is an enlargement of the Kauffman category, obtained by adding a generating object corresponding to the quantum spin module.

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 2 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Type $B$ Webs

    math.RT 2026-07 conditional novelty 7.0 of 10

    Type B webs give a complete diagrammatic presentation of the subcategory of U_q(so_{2n+1})-representations generated by the fundamental representations.

  2. A Kohno--Drinfeld Theorem for iquantum Weyl groups

    math.QA 2026-08 conditional novelty 6.0 of 10

    For the split symmetric pair so_m ⊂ sl_m, the monodromy of the boundary Casimir connection is isomorphic to the iota-quantum Weyl group representation.

Reference graph

Works this paper leans on

29 extracted references · 13 canonical work pages · cited by 2 Pith papers

  1. [1]

    Aboumrad

    W. Aboumrad. Skew H owe duality for types BD via q - C lifford algebras. 2022. http://arxiv.org/abs/2208.09773 arXiv:2208.09773

  2. [2]

    Bodish, B

    E. Bodish, B. Elias, and D. E. V. Rose. Spin link homology. 2024. http://arxiv.org/abs/2407.00189 arXiv:2407.00189

  3. [3]

    Bodish and H

    E. Bodish and H. Wu. Webs for the quantum orthogonal group. 2023. http://arxiv.org/abs/2309.03623 arXiv:2309.03623

  4. [4]

    Webs and quantum skew H owe duality

    Sabin Cautis, Joel Kamnitzer, and Scott Morrison. Webs and quantum skew H owe duality. Math. Ann. , 360(1-2):351--390, 2014. http://arxiv.org/abs/1210.6437 arXiv:1210.6437 , https://doi.org/10.1007/s00208-013-0984-4 doi:10.1007/s00208-013-0984-4

  5. [5]

    Chari and A

    V. Chari and A. Pressley. A guide to quantum groups . Cambridge University Press, Cambridge, 1995. Corrected reprint of the 1994 original

  6. [6]

    P. Deligne. La cat\' e gorie des repr\' e sentations du groupe sym\' e trique S_t , lorsque t n'est pas un entier naturel. In Algebraic groups and homogeneous spaces , volume 19 of Tata Inst. Fund. Res. Stud. Math. , pages 209--273. Tata Inst. Fund. Res., Mumbai, 2007

  7. [7]

    J. T. Ding and Igor B. Frenkel. Spinor and oscillator representations of quantum groups. In Lie theory and geometry , volume 123 of Progr. Math. , pages 127--165. Birkh\" a user Boston, Boston, MA, 1994. https://doi.org/10.1007/978-1-4612-0261-5\_5 doi:10.1007/978-1-4612-0261-5\_5

  8. [8]

    Dipper, J

    R. Dipper, J. Hu, and F. Stoll. Symmetrizers and antisymmetrizers for the BMW -algebra. J. Algebra Appl. , 12(7):1350032, 22, 2013. http://arxiv.org/abs/1109.0342 arXiv:1109.0342 , https://doi.org/10.1142/S0219498813500321 doi:10.1142/S0219498813500321

Show all 29 references
  1. [9]

    A. M. Gavrilik and A. U. Klimyk. q -deformed orthogonal and pseudo-orthogonal algebras and their representations. Lett. Math. Phys. , 21(3):215--220, 1991. http://arxiv.org/abs/math/0203201 arXiv:math/0203201 , https://doi.org/10.1007/BF00420371 doi:10.1007/BF00420371

  2. [10]

    M. Gao, H. Rui, and L. Song. A basis theorem for the affine K auffman category and its cyclotomic quotients. J. Algebra , 608:774--846, 2022. http://arxiv.org/abs/2006.09626 arXiv:2006.09626 , https://doi.org/10.1016/j.jalgebra.2022.07.005 doi:10.1016/j.jalgebra.2022.07.005

  3. [11]

    T. Hayashi. q -analogues of C lifford and W eyl algebras---spinor and oscillator representations of quantum enveloping algebras. Comm. Math. Phys. , 127(1):129--144, 1990. URL: http://projecteuclid.org/euclid.cmp/1104180043

  4. [12]

    Heckenberger and A

    I. Heckenberger and A. Sch\" u ler. Symmetrizer and antisymmetrizer of the B irman- W enzl- M urakami algebras. Lett. Math. Phys. , 50(1):45--51, 1999. http://arxiv.org/abs/math/0002170 arXiv:math/0002170 , https://doi.org/10.1023/A:1007675821808 doi:10.1023/A:1007675821808

  5. [13]

    Klimyk and K

    A. Klimyk and K. Schm\"udgen. Quantum groups and their representations . Texts and Monographs in Physics. Springer-Verlag, Berlin, 1997. https://doi.org/10.1007/978-3-642-60896-4 doi:10.1007/978-3-642-60896-4

  6. [14]

    G. Letzter. Subalgebras which appear in quantum I wasawa decompositions. Canad. J. Math. , 49(6):1206--1223, 1997. https://doi.org/10.4153/CJM-1997-059-4 doi:10.4153/CJM-1997-059-4

  7. [15]

    a user Classics. Birkh\

    G. Lusztig. Introduction to quantum groups . Modern Birkh\" a user Classics. Birkh\" a user/Springer, New York, 2010. Reprint of the 1994 edition. https://doi.org/10.1007/978-0-8176-4717-9 doi:10.1007/978-0-8176-4717-9

  8. [16]

    G. I. Lehrer and R. B. Zhang. The B rauer category and invariant theory. J. Eur. Math. Soc. (JEMS) , 17(9):2311--2351, 2015. http://arxiv.org/abs/1207.5889 arXiv:1207.5889 , https://doi.org/10.4171/JEMS/558 doi:10.4171/JEMS/558

  9. [17]

    Mousaaid and A

    Y. Mousaaid and A. Savage. Affinization of monoidal categories. J. \' E c. polytech. Math. , 8:791--829, 2021. http://arxiv.org/abs/2010.13598 arXiv:2010.13598 , https://doi.org/10.5802/jep.158 doi:10.5802/jep.158

  10. [18]

    P. J. McNamara and A. Savage. The spin B rauer category. Forum Math. Sigma , 12:Paper No. e98, 2024. http://arxiv.org/abs/2312.11766 arXiv:2312.11766 , https://doi.org/10.1017/fms.2024.102 doi:10.1017/fms.2024.102

  11. [19]

    Noumi and T

    M. Noumi and T. Sugitani. Quantum symmetric spaces and related q -orthogonal polynomials. In Group theoretical methods in physics ( T oyonaka, 1994) , pages 28--40. World Sci. Publ., River Edge, NJ, 1995. http://arxiv.org/abs/math/9503225 arXiv:math/9503225

  12. [20]

    R. C. Orellana and H. G. Wenzl. q -centralizer algebras for spin groups. J. Algebra , 253(2):237--275, 2002. https://doi.org/10.1016/S0021-8693(02)00069-8 doi:10.1016/S0021-8693(02)00069-8

  13. [21]

    S ageMath, the S age M athematics S oftware S ystem ( V ersion 9.5) , 2025

    The Sage Developers . S ageMath, the S age M athematics S oftware S ystem ( V ersion 9.5) , 2025. URL: https://www.sagemath.org

  14. [22]

    Selinger

    P. Selinger. A survey of graphical languages for monoidal categories. In New structures for physics , volume 813 of Lecture Notes in Phys. , pages 289--355. Springer, Heidelberg, 2011. http://arxiv.org/abs/0908.3347 arXiv:0908.3347 , https://doi.org/10.1007/978-3-642-12821-9\_...

  15. [23]

    Sartori and D

    A. Sartori and D. Tubbenhauer. Webs and q - H owe dualities in types BCD . Trans. Amer. Math. Soc. , 371(10):7387--7431, 2019. http://arxiv.org/abs/1701.02932 arXiv:1701.02932 , https://doi.org/10.1090/tran/7583 doi:10.1090/tran/7583

  16. [24]

    Savage and B

    A. Savage and B. W. Westbury. Quantum diagrammatics for F_4 . J. Pure Appl. Algebra , 228(11):Paper No. 107731, 35, 2024. http://arxiv.org/abs/2204.11976 arXiv:2204.11976 , https://doi.org/10.1016/j.jpaa.2024.107731 doi:10.1016/j.jpaa.2024.107731

  17. [25]

    V. G. Turaev. Operator invariants of tangles, and R -matrices. Izv. Akad. Nauk SSSR Ser. Mat. , 53(5):1073--1107, 1135, 1989. https://doi.org/10.1070/IM1990v035n02ABEH000711 doi:10.1070/IM1990v035n02ABEH000711

  18. [26]

    Tuba and H

    I. Tuba and H. Wenzl. On braided tensor categories of type BCD . J. Reine Angew. Math. , 581:31--69, 2005. http://arxiv.org/abs/math/0301142 arXiv:math/0301142 , https://doi.org/10.1515/crll.2005.2005.581.31 doi:10.1515/crll.2005.2005.581.31

  19. [27]

    H. Wenzl. On centralizer algebras for spin representations. Comm. Math. Phys. , 314(1):243--263, 2012. http://arxiv.org/abs/1107.4183 arXiv:1107.4183 , https://doi.org/10.1007/s00220-012-1494-z doi:10.1007/s00220-012-1494-z

  20. [28]

    H. Wenzl. Dualities for spin representations. 2020. http://arxiv.org/abs/2005.11299 arXiv:2005.11299

  21. [29]

    B. W. Westbury. Invariant tensors for the spin representation of so (7) . Math. Proc. Cambridge Philos. Soc. , 144(1):217--240, 2008. http://arxiv.org/abs/math/0601209 arXiv:math/0601209 , https://doi.org/10.1017/S0305004107000722 doi:10.1017/S0305004107000722

Pith tools

Reviewed August 16, 2026 · model on record in the stance chip above.