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arxiv: 2512.17314 · v3 · submitted 2025-12-19 · 🧮 math.GN · math.DS· math.FA

Circular orders: topology and continuous actions

Pith reviewed 2026-05-16 21:13 UTC · model grok-4.3

classification 🧮 math.GN math.DSmath.FA
keywords circular ordersuniform structurescompactificationsgroup actionstopological dynamicsHelly selection theorembounded variationorder topology
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The pith

Circular orders admit convex uniform structures that describe their compactifications and continuous group actions.

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

The paper develops a topological theory for circularly ordered sets by equipping them with convex uniform structures compatible with the order. This approach describes circularly ordered compactifications and enables analysis of continuous actions by topological groups on these spaces. It provides a uniform treatment of Novak's regular completion and generates new results on G-compactifications for group actions on abstract ordered spaces. The work also generalizes Helly's selection theorem to functions of bounded variation defined on circular and linear orders. These elements form part of a broader program linking circular orders to tame dynamical systems.

Core claim

Circularly ordered sets carry convex uniform structures that are compatible with their order topology. These structures permit the construction of circularly ordered compactifications and support continuous actions by topological groups. The uniform framework supplies a topological analysis of Novak's regular completion and its associated uniformity. It produces several new theorems about G-compactifications of actions on ordered spaces and yields generalizations of Helly's selection theorem for bounded variation functions on both circular and linear orders.

What carries the argument

The convex uniform structure on a circular order, which encodes order relations via convex sets and ensures uniform continuity for maps and actions.

If this is right

  • New results in the theory of G-compactifications for topological group actions on abstract ordered spaces.
  • A topological analysis of Novak's regular completion and its uniformity.
  • Generalizations of Helly's selection theorem for functions of bounded variation on circular and linear orders.
  • A systematic framework for studying continuous group actions on generalized circularly ordered topological spaces.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The uniform-structure method may extend naturally to other ordered spaces that lie between linear and circular orders.
  • Concrete computations with the circle group acting on standard circular orders could verify continuity of the induced actions.
  • The approach supplies tools that might classify minimal tame actions on compact circular orders.
  • Links to dynamical systems suggest the framework could help distinguish tame from non-tame behavior via order properties.

Load-bearing premise

Circularly ordered sets can be given compatible topologies and convex uniform structures that support the required compactifications and continuous actions without further restrictions.

What would settle it

A concrete circularly ordered set for which no compatible convex uniform structure exists that admits a G-compactification for some topological group action, or on which the generalized Helly theorem fails for bounded variation functions.

Figures

Figures reproduced from arXiv: 2512.17314 by Michael Megrelishvili.

Figure 1
Figure 1. Figure 1: c-ordered lexicographic product (from Wikipedia - Cyclic order ) Definition 5.2. More formally, let (a, x),(b, y),(c, z) be distinct points of C×L. Then [(a, x),(b, y),(c, z)] in C ⊗c L will mean that one of the following conditions is satisfied: (1) [a, b, c]. (2) a = b ̸= c and x < y. (3) b = c ̸= a and y < z. (4) c = a ̸= b and z < x. (5) a = b = c and [x, y, z] (in the cyclic order on L induced by the … view at source ↗
Figure 2
Figure 2. Figure 2: Geometric description of βG(Q0) (3) βG(Q0) = M(G) ∪ Q0 and M(G) = split(T, Q0) is the universal minimal G-system of G. Geometrically, M(G) is the circle after splitting any rational point (removing isolated q from that triple q −, q, q+). Recall that the Polish topological group H+(T, ◦) is Roelcke precompact [32]. The same is true for Aut(Q0, ◦) [35]). Several important generalizations of these results ca… view at source ↗
Figure 3
Figure 3. Figure 3: loxodromic idempotent p pa defined by pax = a, ∀x ∈ T, does not admit a countable basis for its topology. □ In a similar way to the proof of Proposition 13.10, one shows that the G-system M(G) = split(T, Q0) from Fact 5.14.3 is tame but not Tame1. Remark 13.11. Theorems 4.11 and 13.8 cannot be extended, in general, to circular orders. Indeed, the “circular analog of Helly’s space” M+(T, T) (which is a sepa… view at source ↗
read the original abstract

We study the topology of circularly ordered sets. While the algebraic notion is classical, the general topological theory has received comparatively little attention. In this work we provide a self-contained topological exposition and present several new directions and results. Our aim is to initiate a systematic study of generalized circularly ordered topological spaces and of continuous group actions on them. Provide a convex uniform structure description of circularly ordered compactifications. This yields a topological analysis of Novak's regular completion and its uniformity. Demonstrate that this uniform-structure approach yields several new results in the theory of $G$-compactifications for topological group actions on abstract ordered spaces. Reexamine functions of bounded variation on circularly ordered sets and prove generalizations of Helly's selection theorem (for circular and linear orders). These developments and the systematic analysis of circular order topologies are motivated by recent applications in topological dynamics, particularly in joint works with Eli Glasner, which demonstrate that circularly ordered dynamical systems provide a natural class of tame dynamics.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The paper offers a self-contained topological study of circularly ordered sets, equipping them with compatible topologies and convex uniform structures to describe their compactifications (including a topological analysis of Novak's regular completion). It uses this framework to obtain new results on G-compactifications for continuous actions of topological groups on abstract ordered spaces, reexamines functions of bounded variation, and proves generalizations of Helly's selection theorem for both circular and linear orders. The developments are motivated by applications to tame dynamics in joint work with Glasner.

Significance. If the uniform-structure constructions hold, the work supplies a systematic, topology-first approach to circular orders that could unify and extend results on compactifications and continuous group actions, with direct relevance to topological dynamics. The generalizations of Helly's theorem and the G-compactification applications represent concrete advances that build on the authors' prior joint results.

major comments (2)
  1. [Section 3] Section 3: The construction of the convex uniform structure via entourages generated by convex sets implicitly assumes that order intervals are closed in the induced topology and that the uniformity is Hausdorff and complete. These properties are not verified for arbitrary (including non-separable or non-linearly-orderable) circular orders, which is load-bearing for the claim that every continuous G-action extends continuously to the compactification.
  2. [§4–5] The G-compactification results (abstract and §4–5): it is not shown whether the uniform continuity of the action on the base space follows automatically from the convex uniformity or requires additional separation/density hypotheses; without this, the extension theorem does not follow in full generality.
minor comments (2)
  1. [Abstract] The abstract repeats the phrase 'uniform-structure approach' without defining the uniformity until later sections; a brief forward reference would improve readability.
  2. [Section 2] Notation for convex entourages and the regular completion should be introduced with a short table or diagram for clarity, especially when comparing linear and circular cases.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the careful and constructive comments on our manuscript. We address the major comments point by point below, and we plan to incorporate clarifications and additional verifications in the revised version.

read point-by-point responses
  1. Referee: Section 3: The construction of the convex uniform structure via entourages generated by convex sets implicitly assumes that order intervals are closed in the induced topology and that the uniformity is Hausdorff and complete. These properties are not verified for arbitrary (including non-separable or non-linearly-orderable) circular orders, which is load-bearing for the claim that every continuous G-action extends continuously to the compactification.

    Authors: We acknowledge this point and agree that explicit verification strengthens the manuscript. In the revised version, we will insert a new lemma in Section 3 proving that for any circular order, the order intervals are closed in the topology induced by the convex uniformity, and that the uniformity is Hausdorff and complete. The proof relies on the convexity of the entourages and the circular order axioms, and it applies to non-separable cases without requiring linear orderability. This will directly support the continuous extension of G-actions to the compactification. revision: yes

  2. Referee: The G-compactification results (abstract and §4–5): it is not shown whether the uniform continuity of the action on the base space follows automatically from the convex uniformity or requires additional separation/density hypotheses; without this, the extension theorem does not follow in full generality.

    Authors: Upon re-examination, the uniform continuity does follow automatically from the continuity of the action with respect to the convex uniformity, without needing extra hypotheses, because the entourages are defined to be convex and thus compatible with the group action's continuity. However, we concede that this was not sufficiently explicit in the text. In the revision, we will add a proposition in Section 4 that derives the uniform continuity directly from the given continuity and the uniformity's properties, thereby confirming the extension theorem holds in full generality for arbitrary circular orders. revision: yes

Circularity Check

0 steps flagged

Self-contained exposition with non-load-bearing references to prior joint work

full rationale

The paper develops its core results from the algebraic definition of circular orders by constructing compatible topologies and convex uniform structures directly via entourages from convex sets, then deriving compactifications, Novak completions, and G-action extensions within the manuscript. These steps rely on standard uniform space properties and order interval closures without reducing any prediction or new theorem to a fitted input or self-referential definition. Citations to joint work with Glasner appear only in the motivation for dynamical applications and do not justify the topological constructions or uniqueness claims, leaving the derivation chain independent and self-contained.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The paper relies on classical notions of circular orders and standard topological axioms; no free parameters, invented entities, or ad-hoc axioms are indicated in the abstract.

axioms (1)
  • standard math Standard axioms of set theory, topology, and order theory for circular orders
    The exposition builds directly on classical algebraic definitions of circular orders and topological spaces.

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Forward citations

Cited by 1 Pith paper

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

  1. Intrinsic uniform structure on median algebras

    math.GN 2026-05 unverdicted novelty 7.0

    Defines the median uniformity U_m on median algebras to construct the Minimal Median Compactification (MMC) as a natural compactification for group actions by median automorphisms, with uniqueness and tameness results...

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Works this paper leans on

84 extracted references · 84 canonical work pages · cited by 1 Pith paper · 1 internal anchor

  1. [1]

    Arens,Topologies for homeomorphism groups, Amer

    R. Arens,Topologies for homeomorphism groups, Amer. J. of Math.,68(4) (1946), 593–610

  2. [2]

    Bass, M.V

    H. Bass, M.V. Otero-Espinar, D. Rockmore, C. Tresser,Cyclic Renormalization and Automorphism Groups of Rooted Trees, Lecture Notes in Math. 1621, Springer, 1995

  3. [3]

    Belov and V.V

    S.A. Belov and V.V. Chistyakov,A selection principle for mappings of bounded variation, J. Math. Anal. Appl. 249 (2000), 351–366

  4. [4]

    Bennett, D.J

    H.R. Bennett, D.J. Lutzer,Recent Developments in the Topology of Ordered Spaces, Chapter 3 in: Recent Progress in General Topology II (2002), Ed.: M. Husek and J. van Mill, Elsevier

  5. [5]

    Borubaev,Uniform Spaces and Uniformly Continuous Mappings, Frunze, Ilim, 1990 (Russian)

    A.A. Borubaev,Uniform Spaces and Uniformly Continuous Mappings, Frunze, Ilim, 1990 (Russian)

  6. [6]

    Buhagiar and T

    D. Buhagiar and T. Miwa,Ordered uniform completions of GO-spaces, Topology Proc.22(1997), 59–80

  7. [7]

    Bezhanishvili and P.J

    G. Bezhanishvili and P.J. Morandi,Order-Compactifications of Totally Ordered Spaces: Revisited, Order28 (2011), 577–592 47

  8. [8]

    Blatter,Order compactifications of totally ordered topological spaces, J

    C. Blatter,Order compactifications of totally ordered topological spaces, J. Approx. Theory13(1975), 56–65

  9. [9]

    Bourgain,Some remarks on compact sets of first Baire class

    J. Bourgain,Some remarks on compact sets of first Baire class. Bull. Soc. Math. Belg.30(1978), 3–10

  10. [10]

    Bourgain, D.H

    J. Bourgain, D.H. Fremlin and M. Talagrand,Pointwise compact sets in Baire-measurable functions, Amer. J. of Math.,100(1978), n. 4, 845–886

  11. [11]

    Brook,A construction of the greatest ambit, Math

    R.B. Brook,A construction of the greatest ambit, Math. Systems Theory,6(1970), 243–248

  12. [12]

    Calegari,Circular groups, planar groups, and the Euler class, Geometry & Topology Monographs, Volume 7: Proceedings of the Casson Fest, 431–491 (2004)

    D. Calegari,Circular groups, planar groups, and the Euler class, Geometry & Topology Monographs, Volume 7: Proceedings of the Casson Fest, 431–491 (2004)

  13. [13]

    ˇCech,Point Sets, Academia, Prague, 1969

    E. ˇCech,Point Sets, Academia, Prague, 1969

  14. [14]

    ˇCernak, J

    S. ˇCernak, J. ˇJakubˇik,Completion of a cyclically ordered group, Czech. Math. J.37(1987), 157–174

  15. [15]

    Chistyakov,Selections of bounded variation, Journal of Applied Analysis, 10 (2004), 1–82

    V.V. Chistyakov,Selections of bounded variation, Journal of Applied Analysis, 10 (2004), 1–82

  16. [16]

    A. Clay, D. Rolfsen,Ordered Groups and Topology, Graduate Studies in Mathematics176, AMS, 2016

  17. [17]

    Deroin, A

    B. Deroin, A. Navas and C. Rivas,Groups, Orders and Dynamics,arXiv:1408.5805 (2016)

  18. [18]

    van Dulst,Characterizations of Banach spaces not containingl 1, Centrum voor Wiskunde en Informatica, Amsterdam, 1989

    D. van Dulst,Characterizations of Banach spaces not containingl 1, Centrum voor Wiskunde en Informatica, Amsterdam, 1989

  19. [19]

    Ellis,Lectures on Topological Dynamics, W

    R. Ellis,Lectures on Topological Dynamics, W. A. Benjamin, Inc. , New York, 1969

  20. [20]

    Engelking,General Topology(revised and completed edition), Heldermann Verlag, Berlin, 1989

    R. Engelking,General Topology(revised and completed edition), Heldermann Verlag, Berlin, 1989

  21. [21]

    Fedorchuk,Ordered spaces,Soviet Math

    V. Fedorchuk,Ordered spaces,Soviet Math. Dokl., 7 (1966), 1011–1014

  22. [22]

    Fedorchuk,Ordered proximity spaces,Math

    V. Fedorchuk,Ordered proximity spaces,Math. Notes4(6) (1968) 887–890

  23. [23]

    Font and M

    J.J. Font and M. Sanchis, Sequentially compact subsets and monotone functions: an application to Fuzzy Theory, Topology and its Applications, V. 192, 2015, Pages 113–122

  24. [24]

    Fuchino and Sz

    S. Fuchino and Sz. Plewik,On a theorem of E. Helly, Proc. Amer. Math. Soc.127(2) (1999), 491–497

  25. [25]

    Ghys,Groups acting on the circle, L’Enseignement Mathematique47(2001), 329–407

    E. Ghys,Groups acting on the circle, L’Enseignement Mathematique47(2001), 329–407

  26. [26]

    Glasner,Enveloping semigroups in topological dynamics, Topology Appl.154(2007), 2344–2363

    E. Glasner,Enveloping semigroups in topological dynamics, Topology Appl.154(2007), 2344–2363

  27. [27]

    Glasner and M

    E. Glasner and M. Megrelishvili,Linear representations of hereditarily non-sensitive dynamical systems, Colloq. Math.104(2006), no. 2, 223–283

  28. [28]

    Glasner and M

    E. Glasner and M. Megrelishvili,New algebras of functions on topological groups arising fromG-spaces, Funda- menta Math.,201(2008), 1–51

  29. [29]

    Glasner and M

    E. Glasner and M. Megrelishvili,Representations of dynamical systems on Banach spaces not containingl 1, Trans. Amer. Math. Soc.,364(2012), 6395–6424

  30. [30]

    Glasner and M

    E. Glasner and M. Megrelishvili,Banach representations and affine compactifications of dynamical systems, in: Fields institute proceedings dedicated to the 2010 thematic program on asymptotic geometric analysis, M. Ludwig, V.D. Milman, V. Pestov, N. Tomczak-Jaegermann (Editors), Springer, New-York, 2013

  31. [31]

    Glasner and M

    E. Glasner and M. Megrelishvili,Representations of dynamical systems on Banach spaces,in: Recent Progress in General Topology III, (Eds.: K.P. Hart, J. van Mill, P. Simon), Springer-Verlag, Atlantis Press, 2014, 399-470

  32. [32]

    Eventual nonsensitivity and tame dynamical systems

    E. Glasner and M. Megrelishvili,Eventual nonsensitivity and tame dynamical systems, arXiv:1405.2588, 2014

  33. [33]

    Glasner and M

    E. Glasner and M. Megrelishvili,More on tame dynamical systems, in: Lecture Notes S. vol. 2013, Ergodic Theory and Dynamical Systems in their Interactions with Arithmetics and Combinatorics, Eds.: S. Ferenczi, J. Kulaga-Przymus, M. Lemanczyk, Springer, 2018, pp. 351–392

  34. [34]

    Glasner and M

    E. Glasner and M. Megrelishvili,Circularly ordered dynamical systems,Monats. Math.185(2018), 415–441

  35. [35]

    Glasner and M

    E. Glasner and M. Megrelishvili,Circular orders, ultrahomogeneity and topological groups, ArXiv:1803.06583,

  36. [36]

    Vershik, V.M

    AMS Contemporary Mathematics book series volume772”Topology, Geometry, and Dynamics: Rokhlin- 100” (ed.: A.M. Vershik, V.M. Buchstaber, A.V. Malyutin) 2021, pp. 133–154

  37. [37]

    Glasner and M

    E. Glasner and M. Megrelishvili,Todor˘ cevi´ c’ Trichotomy and a hierarchy in the class of tame dynamical systems, Trans. Amer. Math. Soc.375, 4513–4548 (2022)

  38. [38]

    Glasner, M

    E. Glasner, M. Megrelishvili and V.V. Uspenskij,On metrizable enveloping semigroups, Israel Journal of Math., 164, 317–332 (2008)

  39. [39]

    Hindman, R.D

    N. Hindman, R.D. Kopperman,Order compactifications of discrete semigroups, Topology Proc.27, 479–496 (2003)

  40. [40]

    Heath, D.J

    R.W. Heath, D.J. Lutzer and P.L. Zenor,Monotonically Normal Spaces, Trans. Amer. Math. Soc.178(1973), 481–493

  41. [41]

    Huntington,A set of independent postulates for cyclic order,Proceedings of the National Academy of Sciences of the United States of America,2(1916), 630–631

    E.V. Huntington,A set of independent postulates for cyclic order,Proceedings of the National Academy of Sciences of the United States of America,2(1916), 630–631

  42. [42]

    Huntington,Sets of completely independent postulates for cyclic order,Proceedings of the National Academy of Sciences of the United States of America,10(1924), 74–78

    E.V. Huntington,Sets of completely independent postulates for cyclic order,Proceedings of the National Academy of Sciences of the United States of America,10(1924), 74–78

  43. [43]

    Isbell,Uniform spaces, Providence, 1964

    J. Isbell,Uniform spaces, Providence, 1964

  44. [44]

    Kaufman,Ordered sets and compact spaces, Colloq

    R. Kaufman,Ordered sets and compact spaces, Colloq. Math.17(1967), 35–39

  45. [45]

    Kemoto,The lexicographic ordered products and the usual Tychonoff products,Topology Appl.162(2014), 20–33

    N. Kemoto,The lexicographic ordered products and the usual Tychonoff products,Topology Appl.162(2014), 20–33

  46. [46]

    Kent and T.R

    D.C. Kent and T.R. Richmond,Ordered compactification of totally ordered spaces, Internat. J. Math. Math. Sci. 11(1988), 683–694

  47. [47]

    Kok,Connected orderable spaces, Math

    H. Kok,Connected orderable spaces, Math. Centhre Tracts49, Math. Cent. Tracts, Amsterdam, 1973

  48. [48]

    K¨ ohler,Enveloping semigroups for flows, Proc

    A. K¨ ohler,Enveloping semigroups for flows, Proc. of the Royal Irish Academy,95A(1995), 179–191

  49. [49]

    Kozlov and B.V

    K.L. Kozlov and B.V. Sorin,Enveloping semigroups as compactifications of topological groups, 2025, arXiv:2509.17577 48

  50. [50]

    Lutzer, H.R

    D.J. Lutzer, H.R. Bennett,Separability, the countable chain condition and the Lindelof property in linearly orderable spaces, Proc. AMS,23(1969), pp. 664–667

  51. [51]

    McMullen, RibbonR-trees and holomorphic dynamics on the unit disk, J

    C. McMullen, RibbonR-trees and holomorphic dynamics on the unit disk, J. of Topology, v. 2, 2009, p. 23–76

  52. [52]

    Megrelishvili,Equivariant completions and compact extensions, Bull

    M. Megrelishvili,Equivariant completions and compact extensions, Bull. Ac. Sc. Georgian SSR,115:1(1984), 21–24

  53. [53]

    Megrelishvili,A Tychonoff G-space not admitting a compact Hausdorff G-extension or a G-linearization, Russian Math

    M. Megrelishvili,A Tychonoff G-space not admitting a compact Hausdorff G-extension or a G-linearization, Russian Math. Surveys43:2(1988), 177–178

  54. [54]

    Megrelishvili,Fragmentability and representations of flows, Topology Proceedings,27:2(2003), 497–544

    M. Megrelishvili,Fragmentability and representations of flows, Topology Proceedings,27:2(2003), 497–544. For the updated version see arXiv:math/0411112

  55. [55]

    Megrelishvili,Compactifications of semigroups and semigroup actions, Topology Proc.31:2(2007), 611–650

    M. Megrelishvili,Compactifications of semigroups and semigroup actions, Topology Proc.31:2(2007), 611–650

  56. [56]

    Megrelishvili,Topological transformation groups: selected topics

    M. Megrelishvili,Topological transformation groups: selected topics. In: Open Problems in Topology II (Elliott Pearl, editor), Elsevier Science, 2007, pp. 423–438

  57. [57]

    Megrelishvili,A note on tameness of families having bounded variation, Topology Appl.217(2017), 20–30

    M. Megrelishvili,A note on tameness of families having bounded variation, Topology Appl.217(2017), 20–30

  58. [58]

    Megrelishvili,Median pretrees and functions of bounded variation, Topology Appl.285(2020)

    M. Megrelishvili,Median pretrees and functions of bounded variation, Topology Appl.285(2020)

  59. [59]

    Megrelishvili,Orderable groups and semigroup compactifications,Monatsch

    M. Megrelishvili,Orderable groups and semigroup compactifications,Monatsch. Math.200(2022), 903–932

  60. [60]

    Megrelishvili,Maximal equivariant compactifications, Topology Appl.329(2023), 108372

    M. Megrelishvili,Maximal equivariant compactifications, Topology Appl.329(2023), 108372

  61. [61]

    Megrelishvili,Topological Group Actions and Banach Representations, unpublished book, Available on au- thor’s homepage, 2025

    M. Megrelishvili,Topological Group Actions and Banach Representations, unpublished book, Available on au- thor’s homepage, 2025

  62. [62]

    Megrelishvili,Key subgroups in the Polish group of all automorphisms of the rational circle, arXiv:2410.17905, 2024

    M. Megrelishvili,Key subgroups in the Polish group of all automorphisms of the rational circle, arXiv:2410.17905, 2024

  63. [63]

    T. Miwa, N. Kemoto, Linearly ordered extensions of GO spaces, Topology Appl.54(1993), 133–140

  64. [64]

    Nachbin,Topology and order,Van Nostrand Math

    L. Nachbin,Topology and order,Van Nostrand Math. Studies, Princeton, New Jersey, 1965

  65. [65]

    Nagata,Modern General Topology, North Holland, 1985

    J. Nagata,Modern General Topology, North Holland, 1985

  66. [66]

    Natanson,Theory of functions of real variable, v

    I.P. Natanson,Theory of functions of real variable, v. I, New York, 1964

  67. [67]

    Namioka,Radon-Nikod´ ym compact spaces and fragmentability, Mathematika 34 (1987), 258–281

    I. Namioka,Radon-Nikod´ ym compact spaces and fragmentability, Mathematika 34 (1987), 258–281

  68. [68]

    Nguyen van Th´ e,More on the Kechris-Pestov-Todorcevic correspondence: precompact expansions, Fund

    L. Nguyen van Th´ e,More on the Kechris-Pestov-Todorcevic correspondence: precompact expansions, Fund. Math. 222(2013), no. 1, 19–47

  69. [69]

    Novak,Cuts in cyclically ordered sets, Czech

    V. Novak,Cuts in cyclically ordered sets, Czech. Math. J.34, 322–333 (1984)

  70. [70]

    Ovchinnikov,Topological automorphism groups of chains, Mathware Soft Comput., v

    S. Ovchinnikov,Topological automorphism groups of chains, Mathware Soft Comput., v. 8, n. 1, 47–60, 2001

  71. [71]

    Pestov,On free actions, minimal flows and a problem by Ellis, Trans

    V. Pestov,On free actions, minimal flows and a problem by Ellis, Trans. Amer. Math. Soc.350(1998), 4149–4165

  72. [72]

    Rosenthal,A characterization of Banach spaces containingl 1, Proc

    H.P. Rosenthal,A characterization of Banach spaces containingl 1, Proc. Nat. Acad. Sci. U.S.A., 71 (1974), 2411–2413

  73. [73]

    Rosenthal,Point-wise compact subsets of the first Baire class, Amer

    H.P. Rosenthal,Point-wise compact subsets of the first Baire class, Amer. J. of Math., 99:2 (1977), 362–378

  74. [74]

    Pestov,A topological transformation group without non-trivial equivariant compactifications, Advances in Math.311(2017), 1–17

    V. Pestov,A topological transformation group without non-trivial equivariant compactifications, Advances in Math.311(2017), 1–17

  75. [75]

    Sorin,Compactifications of Homeomorphism Groups of Linearly Ordered Compacta, Math

    B.V. Sorin,Compactifications of Homeomorphism Groups of Linearly Ordered Compacta, Math. Notes,112 (2022)

  76. [76]

    Sorin, The Roelcke Precompactness and Compactifications of Transformations Groups of Discrete Spaces and Homogeneous Chains, 2023, arXiv:2310.18570

    G.B. Sorin, The Roelcke Precompactness and Compactifications of Transformations Groups of Discrete Spaces and Homogeneous Chains, 2023, arXiv:2310.18570

  77. [77]

    Sorin,Lattices of Extensions of Cyclically Ordered Sets and Compactifications of Generalized Cyclically Ordered Spaces, Mathematical Notes, 116 (2024), 763–776

    G.B. Sorin,Lattices of Extensions of Cyclically Ordered Sets and Compactifications of Generalized Cyclically Ordered Spaces, Mathematical Notes, 116 (2024), 763–776

  78. [78]

    Sorin, Semigroup compactifications of groups of automorphisms of ultra-homogeneous cyclically ordered sets, Math

    G.B. Sorin, Semigroup compactifications of groups of automorphisms of ultra-homogeneous cyclically ordered sets, Math. Sbornik (in Russian), 217:2 (2026), 154–179

  79. [79]

    Steen, J.A

    L.A. Steen, J.A. Seebach,Counterexamples in Topology, Dover Publications, New York, 1978

  80. [80]

    Struve,Cyclic order: a geometric analysis,Beitr¨ age zur Algebra und Geometrie,61(2020), 649–669

    R. Struve,Cyclic order: a geometric analysis,Beitr¨ age zur Algebra und Geometrie,61(2020), 649–669

Showing first 80 references.