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A unified approach to cross-intersection problems with applications to Hilton--Milner type theorems and stability

T0 review · 0 major / 5 minor · reviewed 2026-07-12 · grok-4.5

Pith's one-line read A peeling-and-t-cover method determines the largest cross t-intersecting set families and their t-diversity for large n.

desk verdict Solid combinatorial paper that actually delivers the natural t≥2 max-min, product, and diversity extensions of the classical Hilton–Milner / Mörs–Füredi / Frankl results, with a usable fingerprint+t-cover method and explicit (if quadratic) n-thresholds. read the letter →

arxiv 2607.03315 v1 pith:LI3X4B4C submitted 2026-07-03 math.CO

classification math.CO MSC 05D05
keywords crosst-intersectingfamiliesHilton–Milnertheoremt-diversityfingerprintiterationt-covermethodspreadapproximationErdős–Ko–Radostability
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

The paper supplies a single iterative procedure that turns any pair of cross t-intersecting families into a short sequence of "fingerprints" (minimal t-covers). Those fingerprints feed classical t-cover estimates and immediately yield sharp upper bounds on both the min-size and the product of sizes of the original families, once n is large enough relative to k and t. The same machinery produces a stability theory measured by a new parameter called t-diversity: the number of sets that avoid the most popular t-set. As corollaries one recovers Hilton–Milner-type theorems for every t≥2, an improved product version of the Hilton–Milner theorem, and a large-n form of a stability conjecture of Ellis–Keller–Lifshitz. The method also works for any ambient family that is sufficiently "spread," giving product Erdős–Ko–Rado theorems for signed sets and for partitions.

What carries the argument

The fingerprint iteration: starting from a maximal cross t-intersecting pair, one repeatedly replaces each family by a fingerprint of its minimal t-covers of successive sizes; the resulting layers are small by spread estimates, and the terminal fingerprint is simple enough that classical t-cover degree bounds finish the proof.

What would settle it

Exhibit, for some fixed t≥2 and infinitely many k, a pair of cross t-intersecting k-uniform families on n=O(kt) elements whose min-size strictly exceeds both |A(n,k,t)| and |H(n,k,t)|.

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Extended reading notes

Core claim

For k≥t+2≥4 and n larger than a quadratic threshold in k and t, every pair of cross t-intersecting k-uniform families with no common t-set satisfies min{|F|,|G|}≤ max{|A(n,k,t)|,|H(n,k,t)|}, with equality only for the classical Hilton–Milner pairs or the Ahlswede–Khachatrian family A(Z). Parallel statements hold for the product |F||G| and for the new t-diversity measure.

Load-bearing premise

All main theorems need n to grow at least quadratically with k (or linearly in (k-t) times a polynomial in t); the degree bounds fail once n drops below roughly (k-t)^{2}.

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Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

0 major / 5 minor

Summary. The paper develops a unified combinatorial framework for cross t-intersecting families, combining an iterative fingerprint algorithm (inspired by Kupavskii–Zakharov peeling) with the t-cover method. For k-subsets of [n] it proves, under explicit quadratic n-thresholds, a max-min theorem (Thm 1.5) generalizing Mörs–Füredi, a product Hilton–Milner theorem with equality characterization that improves Frankl–Wang (Thm 1.7), and several t-diversity stability results (Thms 1.10, 1.12, 1.14), the last of which gives a large-n form of a conjecture of Ellis–Keller–Lifshitz and a t-analogue of Frankl’s degree theorem. A product EKR statement for weakly (r,t)-spread families (Thm 1.3) is also obtained and applied to signed sets and k-partitions.

Significance. The work supplies the first systematic treatment of cross t-intersecting problems for t≥2 that yields both extremal sizes and structural characterizations, together with a natural t-diversity parameter that unifies several stability statements. The fingerprint algorithm is flexible enough to recover classical Hilton–Milner theorems as special cases and to produce new product and diversity results under fully explicit n-conditions. The proofs are self-contained combinatorial arguments; all binomial inequalities are derived rather than black-boxed, and equality cases are completely classified. The quadratic n-thresholds are a genuine limitation (already noted by the authors in §5.2), but they do not undermine the correctness of the theorems as stated.

minor comments (5)
  1. The n-thresholds appearing in Theorems 1.5, 1.7, 1.10 and 1.12 (the constants 30, 15, 18, 7, 10, …) are obtained by successive crude estimates; a short remark collecting the precise places where each constant is forced would help the reader track possible improvements.
  2. In the statement of Conjecture 1 the authors already note a minor slip in the printed formulation of Ellis–Keller–Lifshitz; it would be cleaner to restate the corrected form once and then refer only to that version.
  3. Lemma 3.5 lists three concrete pairs of 2-uniform families; a one-line verification that these pairs are indeed cross t-intersecting antichains of minimal t-covers would make the subsequent case analysis easier to follow.
  4. The applications in §5.1 (signed sets, k-partitions) are short and correct, but the precise range of q or n for which the classical EKR thresholds are improved could be highlighted more explicitly.
  5. A few typographical inconsistencies appear (e.g., “crosst-intersecting” versus “cross t-intersecting”, occasional missing spaces around “t-cover”). These are purely cosmetic.

Circularity Check

0 steps flagged · score 0.0 of 10

No circularity: pure combinatorial derivation from definitions of cross t-intersection, maximality and the fingerprint algorithm; extremal constructions are exhibited independently and proved optimal under explicit n-thresholds.

full rationale

The paper develops an iterative fingerprint algorithm (Section 2) that produces sequences of minimal t-covers from a maximal cross t-intersecting pair, then applies elementary union bounds, binomial estimates (Lemmas 3.1–3.2) and the classical t-cover degree bound (Lemma 3.3) to control the sizes of successive layers. All main theorems (1.5, 1.7, 1.10, 1.12, 1.14) are proved by exhaustive case analysis on the termination index N of the algorithm, comparing the resulting size or diversity bounds against the independently defined constructions A(Z), H(X,K,L) and L(X,U,V). Equality cases are characterized by forcing the fingerprints to coincide with those of the constructions. No parameter is fitted to data; no uniqueness theorem is imported from the authors’ prior work as a hidden premise; the self-citations (to their earlier t-cover paper on partitions) appear only as applications of the new Theorem 1.3. The quadratic n-thresholds are explicit hypotheses of the statements and are used transparently in the estimates; they do not create a definitional loop. The derivation is therefore self-contained and non-circular.

Assumptions & free parameters 1 free parameters · 4 assumptions · 2 invented entities

The paper is pure extremal combinatorics. It rests on standard binomial arithmetic, the classical EKR theorem (cited), maximality of cross-intersecting pairs, and the definition of weak (r,t)-spreadness. No empirical free parameters appear; the numerical thresholds on n are proof artifacts chosen so that certain geometric series and AM-GM comparisons close. The only invented notions are the fingerprint algorithm and t-diversity, both defined explicitly and used only inside the paper’s own arguments.

free parameters (1)
  • n-threshold constants (30, 15, 18, 7, 10, …) = e.g. 30, 15, 18, 7, 10
    Numerical factors such as 30(t+2), 15(t+2)², 7(k−t+1)k² are chosen by hand so that the estimates δ≤0.3(t+1), f(j)<(1−ε)², etc., hold; they are not forced by a uniqueness theorem and could in principle be improved.
assumptions (4)
  • standard math Classical Erdős–Ko–Rado theorem (Theorem 1.1) and Hilton–Milner / Ahlswede–Khachatrian non-trivial intersection theorems for the comparison constructions A and H.
    Invoked as background size benchmarks; proofs of the new theorems do not re-derive EKR.
  • domain assumption A pair of cross t-intersecting families may be enlarged to a maximal pair without decreasing sizes or t-diversities.
    Used throughout Sections 3–4 to justify starting the algorithm from (M(G),M(F)).
  • domain assumption Weak (r,t)-spreadness of the ambient family implies the degree bounds needed for the product EKR (Theorem 1.3).
    Definition taken from Kupavskii; verified for signed sets and k-partitions in Section 5.
  • ad hoc to paper Lemma 3.3 (t-cover size bound) holds whenever n≥(k−t+1)(ℓ−t+1)+t.
    Proved in the paper but is the bottleneck that forces quadratic n; if the lemma could be sharpened the main n-thresholds would improve.
invented entities (2)
  • fingerprint of a cross t-intersecting pair
    purpose: Canonical pair of minimal t-covers that seeds the iterative peeling algorithm and encodes structural information.
    Defined in Lemma 2.2; no external independent evidence required because it is a purely combinatorial construction.
  • t-diversity γ_t(F)
    purpose: Quantitative distance from a family to the nearest full t-star; used for stability statements.
    Natural generalization of ordinary diversity (t=1); defined and studied only inside this paper.

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Pith. "Pith review of A unified approach to cross-intersection problems with applications to Hilton--Milner type theorems and stability." pith.science (2026). https://pith.science/paper/LI3X4B4C

@misc{pith2026260703315,
  author       = {Pith},
  title        = {Pith review of: A unified approach to cross-intersection problems with applications to Hilton--Milner type theorems and stability},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/LI3X4B4C}},
  note         = {Machine review of arXiv:2607.03315}
}
abstract

We develop a new approach to cross-intersection problems in extremal set theory. The method builds on the iterative procedure introduced by Kupavskii and Zakharov (2024) and the $t$-cover method. It provides a flexible framework for deriving extremal and stability results for cross $t$-intersecting families. Our approach applies to a variety of combinatorial objects. As an application, we prove a product version of the seminal Erd\H{o}s--Ko--Rado theorem for sufficiently spread set systems. Two families $\mathcal{F}$ and $\mathcal{G}$ of $k$-subsets of $[n]$ are called cross $t$-intersecting if $|F\cap G|\geq t$ for all $F\in\mathcal{F}$ and $G\in\mathcal{G}$. We determine the families maximizing $\min\{|\mathcal{F}|, |\mathcal{G}|\}$ for large $n$ and all $t\ge2$, generalizing results of M\"{o}rs (1985) and F\"{u}redi (1995) for cross $1$-intersecting families. We then determine the families maximizing $|\mathcal{F}||\mathcal{G}|$ under the condition $\max\{|\cap_{F\in\mathcal{F}}F|,|\cap_{G\in\mathcal{G}}G|\}<t$ for large $n$. This improves the bound obtained by Frankl and Wang (2024), and provides a characterization of extremal configurations. For a family $\mathcal{F}$ of subsets of $[n]$, we introduce its $t$-diversity $\gamma_t(\mathcal{F})$, defined as the minimum number of sets from $\mathcal{F}$ not containing a fixed $t$-subset. This serves as a natural generalization of the important notion of diversity for $t=1$. We obtain a stability result via $\gamma_t$, and determine the maximum of $\min\{\gamma_t(\mathcal{F}),\gamma_t(\mathcal{G})\}$ for cross $t$-intersecting families $\mathcal{F}$ and $\mathcal{G}$. These yield new results for $t$-intersecting families, including a stability theorem towards a conjecture of Ellis, Keller and Lifshitz (2019), which may also be regarded as a $t$-intersection version, for large $n$, of an influential theorem of Frankl (1987).

Figures

Figures reproduced from arXiv: 2607.03315 by the authors.

Figure 1
Figure 1. The first round of the algorithm for the families in (2.2)–(2.4). The following lemma records the basic properties of the output of the algorithm. It gives a decomposition of the input families into successive layers and a terminal fingerprint, together with estimates on the sizes of these layers. These properties serve as an important ingredient in our approach. Lemma 2.3. The following hold for i = 0, 1, . . . , N… view at source ↗

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Cited by 1 Pith paper

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

  1. Erd\H{o}s--Ko--Rado and Hilton--Milner Theorems in the Partition Lattice

    math.CO 2026-08 accept novelty 7.0 of 10

    For intersecting families of rank-k flats in the graphic matroid of K_{n+1}, size is at most binom(n-1,k-1) whenever n+1 >= 8k, with equality only for a full edge-star.

Reference graph

Works this paper leans on

59 extracted references · 6 linked inside Pith · cited by 1 Pith paper

  1. [1]

    Ahlswede and L.H

    R. Ahlswede and L.H. Khachatrian, The complete nontrivial-intersection theorem for sys- tems of finite sets, J. Combin. Theory Ser. A 76 (1996) 121–138

  2. [2]

    Ahlswede and L.H

    R. Ahlswede and L.H. Khachatrian, The complete intersection theorem for systems of finite sets, European J. Combin. 18 (1997) 125–136

  3. [3]

    Alweiss, S

    R. Alweiss, S. Lovett, K. Wu, J. Zhang, Improved bounds for the sunflower lemma, Ann. of Math. 194 (3) (2021) 795–815

  4. [4]

    Balogh and D

    J. Balogh and D. Mubayi, A new short proof of a theorem of Ahlswede and Khachatrian, J. Combin. Theory Ser. A 115 (2008) 326–330

  5. [5]

    Blokhuis, A

    A. Blokhuis, A. Brouwer, A. Chowdhury, P. Frankl, T. Mussche, B. Patk´ os and T. Sz˝ onyi, A Hilton–Milner theorem for vector spaces, Electron. J. Combin. 17 (2010) #R71

  6. [6]

    Bollob´ as and I

    B. Bollob´ as and I. Leader, An Erd˝ os–Ko–Rado theorem for signed sets, Comput. Math. Appl. 34 (1997) 9–13

  7. [7]

    Borg, Ont-intersecting families of signed sets and permutations, Discrete Math

    P. Borg, Ont-intersecting families of signed sets and permutations, Discrete Math. 309 (2009) 3310–3317

  8. [8]

    Borg and I

    P. Borg and I. Leader, Multiple cross-intersecting families of signed sets, J. Combin. Theory Ser. A 117 (2010) 583–588

Show all 59 references
  1. [9]

    M. Cao, B. Lv and K. Wang, The structure of large non-trivialt-intersecting families of finite sets, European J. Combin. 97 (2021) 103373

  2. [10]

    M. Cao, M. Lu, B. Lv and K. Wang, Nearly extremal non-trivial crosst-intersecting families andr-wiset-intersecting families, European J. Combin. 120 (2024) 103958

  3. [11]

    Deza and P

    M. Deza and P. Frankl, The Erd˝ os–Ko–Rado theorem–22 years later, SIAM J. Algebraic Discrete Methods 4 (1983) 419–431

  4. [12]

    Dinur and E

    I. Dinur and E. Friedgut, Intersecting families are essentially contained in juntas, Combin. Probab. Comput. 18 (2009) 107–122

  5. [13]

    Ellis, N

    A. Ellis, N. Keller and N. Lifshitz, Stability versions of Erd˝ os–Ko–Rado type theorems via isoperimetry, J. Eur. Math. Soc. 21 (2019) 3857–3902

  6. [14]

    Ellis, Intersection problems in extremal combinatorics: theorems, techniques and ques- tions old and new, in: Surveys in Combinatorics 2022, in: London Math

    D. Ellis, Intersection problems in extremal combinatorics: theorems, techniques and ques- tions old and new, in: Surveys in Combinatorics 2022, in: London Math. Soc. Lecture Note Ser., vol. 481, Cambridge Univ. Press, Cambridge, 2022, pp. 115–173

  7. [15]

    Ellis, N

    D. Ellis, N. Keller and N. Lifshitz, Stability for the complete intersection theorem, and the forbidden intersection problem of Erd˝ os and S´ os, J. Eur. Math. Soc. 26 (2024) 1611–1654

  8. [16]

    Erd˝ os, C

    P. Erd˝ os, C. Ko and R. Rado, Intersection theorems for systems of finite sets, Quart. J. Math. Oxf. 2 (12) (1961) 313–320

  9. [17]

    Erd˝ os and L.A

    P.L. Erd˝ os and L.A. Sz´ ekely, Erd˝ os–Ko–Rado theorems of higher order, in: I. Alth¨ ofer, N. Cai, G. Dueck, L. Khachatrian, M.S. Pinsker, A. S´ ark¨ ozy, I. Wegener and Z. Zhang (Eds.), Numbers, Information and Complexity, Springer US, Boston, MA, 2000, 117–124

  10. [18]

    Frankl, The Erd˝ os–Ko–Rado theorem is true forn=ckt, in: Combinatorics, Vol

    P. Frankl, The Erd˝ os–Ko–Rado theorem is true forn=ckt, in: Combinatorics, Vol. I, Proc. Fifth Hungarian Colloq., Keszthely, 1976, in: Colloq. Math. Soc. J´ anos Bolyai, vol. 18, North-Holland, 1978, 365–375

  11. [19]

    Frankl, On intersecting families of finite sets, J

    P. Frankl, On intersecting families of finite sets, J. Combin. Theory Ser. A 24 (1978) 146– 161. 43

  12. [20]

    Frankl, Erd˝ os–Ko–Rado theorem with conditions on the maximal degree, J

    P. Frankl, Erd˝ os–Ko–Rado theorem with conditions on the maximal degree, J. Combin. Theory Ser. A 46 (1987) 252–263

  13. [21]

    Frankl, The shifting technique in extremal set theory, in: Surveys in Combinatorics, in: London Math

    P. Frankl, The shifting technique in extremal set theory, in: Surveys in Combinatorics, in: London Math. Soc. Lecture Note Ser., vol. 123, Cambridge Univ. Press, Cambridge, 1987, pp. 81–110

  14. [22]

    Frankl, Antichains of fixed diameter, Moscow J

    P. Frankl, Antichains of fixed diameter, Moscow J. Combin. Number Theory 7 (2017) 189– 219

  15. [23]

    Frankl, Maximum degree and diversity in intersecting hypergraphs, J

    P. Frankl, Maximum degree and diversity in intersecting hypergraphs, J. Combin. Theory Ser. B 144 (2020) 81–94

  16. [24]

    Frankl and Z

    P. Frankl and Z. F¨ uredi, Beyond the Erd˝ os–Ko–Rado theorem, J. Combin. Theory Ser. A 56 (1991) 182–194

  17. [25]

    Frankl and A

    P. Frankl and A. Kupavskii, Sharp results concerning disjoint cross-intersecting families, European J. Combin. 86 (2020) 103089

  18. [26]

    Frankl and A

    P. Frankl and A. Kupavskii, Diversity, J. Combin. Theory Ser. A 182 (2021) 105468

  19. [27]

    Frankl and A

    P. Frankl and A. Kupavskii, The Hajnal and Rothschild problem, arXiv:2502.06699

  20. [28]

    Frankl and N

    P. Frankl and N. Tokushige, Invitation to intersection problems for finite sets, J. Combin. Theory Ser. A 144 (2016) 157–211

  21. [29]

    Frankl and N

    P. Frankl and N. Tokushige, Extremal Problems for Finite Sets, American Mathematical Society, 2018

  22. [30]

    Frankl and J

    P. Frankl and J. Wang, A product version of the Hilton–Milner theorem, J. Combin. Theory Ser. A 200 (2023) 105791

  23. [31]

    Frankl and J

    P. Frankl and J. Wang, A product version of the Hilton–Milner–Frankl theorem, Sci. China Math. 67 (2024) 455–474

  24. [32]

    Frankl and J

    P. Frankl and J. Wang, Improved bounds on the maximum diversity of intersecting families, European J. Combin. 118 (2024) 103885

  25. [33]

    Frankl and J

    P. Frankl and J. Wang, A product version of the Hilton–Milner theorem II, arXiv:2605.09246

  26. [34]

    F¨ uredi, Cross-intersecting families of finite sets, J

    Z. F¨ uredi, Cross-intersecting families of finite sets, J. Combin. Theory Ser. A 72 (1995) 332–339

  27. [35]

    Godsil and K

    C. Godsil and K. Meagher, Erd˝ os–Ko–Rado Theorems: Algebraic Approaches, Cambridge University Press, 2015

  28. [36]

    Hajnal and B

    A. Hajnal and B. Rothschild, A generalization of the Erd˝ os–Ko–Rado theorem on finite set systems, J. Combin. Theory Ser. A 15 (1973), 359–362

  29. [37]

    Hilton, The Erd˝ os–Ko–Rado theorem with valency conditions, Unpublished Manuscript, 1976

    A.J.W. Hilton, The Erd˝ os–Ko–Rado theorem with valency conditions, Unpublished Manuscript, 1976

  30. [38]

    Hilton, An intersection theorem for a collection of families of subsets of a finite set, J

    A.J.W. Hilton, An intersection theorem for a collection of families of subsets of a finite set, J. Lond. Math. Soc. (2) 15 (1977) 369–376

  31. [39]

    Hilton and E.C

    A.J.W. Hilton and E.C. Milner, Some intersection theorems for systems of finite sets, Quart. J. Math. Oxf. 2 (18) (1967) 369–384

  32. [40]

    Huang, Two extremal problems on intersecting families, European J

    H. Huang, Two extremal problems on intersecting families, European J. Combin. 76 (2019) 1–9

  33. [41]

    Keevash, Shadows and intersections: Stability and new proofs, Adv

    P. Keevash, Shadows and intersections: Stability and new proofs, Adv. Math. 218 (2008) 1685–1703. 44

  34. [42]

    Keevash and E

    P. Keevash and E. Long, Stability for vertex isoperimetry in the cube, J. Combin. Theory Ser. B 145 (2020) 113–144

  35. [43]

    Keevash, N

    P. Keevash, N. Lifshitz, E. Long and D. Minzer, Global hypercontractivity and its applica- tions, arXiv:2103.04604

  36. [44]

    Keevash, N

    P. Keevash, N. Lifshitz, E. Long and D. Minzer, Forbidden intersections for codes, J. Lond. Math. Soc. (2) 108 (2023) 2037–2083

  37. [45]

    Keevash, N

    P. Keevash, N. Lifshitz, E. Long and D. Minzer, Hypercontractivity for global functions and sharp thresholds, J. Amer. Math. Soc. 37 (2024) 245–279

  38. [46]

    Keller, A

    N. Keller, A. Kupavskii, N. Lifshitz and O. Sheinfeld, A complete intersection theorem for large permutation groups, arXiv:2607.00318

  39. [47]

    Keller and N

    N. Keller and N. Lifshitz, The junta method for hypergraphs and the Erd˝ os–Chv´ atal simplex conjecture, Adv. Math. 392 (2021) 107991

  40. [48]

    Keller, D

    N. Keller, D. Minzer, E. Long and O. Sheinfeld, Ont-intersecting families of permutations, Adv. Math. 445 (2024) 109650

  41. [49]

    Kupavskii, Diversity of uniform intersecting families, European J

    A. Kupavskii, Diversity of uniform intersecting families, European J. Combin. 74 (2018) 39–47

  42. [50]

    Kupavskii, An almost completet-intersection theorem for permutations

    A. Kupavskii, An almost completet-intersection theorem for permutations. arXiv:2405.07843

  43. [51]

    Kupavskii, Erd˝ os–Ko–Rado type results for partitions via spread approximations, Eu- ropean J

    A. Kupavskii, Erd˝ os–Ko–Rado type results for partitions via spread approximations, Eu- ropean J. Combin. 132 (2026) 104288

  44. [52]

    Kupavskii and D

    A. Kupavskii and D. Zakharov, Regular bipartite graphs and intersecting families, J. Com- bin. Theory Ser. A 155 (2018) 180–189

  45. [53]

    Kupavskii and D

    A. Kupavskii and D. Zakharov, Spread approximations for forbidden intersections problems, Adv. Math. 445 (2024) 109653

  46. [54]

    Lemons and C

    N. Lemons and C. Palmer, The unbalance of set systems, Graphs Combin. 24 (2008) 361– 365

  47. [55]

    M¨ ors, A generalization of a theorem of Kruskal, Graphs Combin

    M. M¨ ors, A generalization of a theorem of Kruskal, Graphs Combin. 1 (N1) (1985) 167–183

  48. [56]

    Saengrungkongka, extremalt-intersecting families of permutations for larget, arXiv:2605.26051

    P. Saengrungkongka, extremalt-intersecting families of permutations for larget, arXiv:2605.26051

  49. [57]

    Wen and B

    J. Wen and B. Lv, Erd˝ os–Ko–Rado theorem and Hilton–Milner type theorem fork- partitions, J. Combin. Theory Ser. A 223 (2026) 106219

  50. [58]

    Wilson, The exact bound in the Erd˝ os–Ko–Rado theorem, Combinatorica 4 (1984) 247–257

    R.M. Wilson, The exact bound in the Erd˝ os–Ko–Rado theorem, Combinatorica 4 (1984) 247–257

  51. [59]

    T. Yao, B. Lv and K. Wang, Large non-trivialt-intersecting families of signed sets, Aus- tralas. J. Combin. 89 (2024) 32–48. 45

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