Hyperplanes in Configurations, decompositions, and Pascal Triangle of Configurations
Pith reviewed 2026-05-24 18:17 UTC · model grok-4.3
The pith
Decompositions resembling Pascal's triangle for binomial configurations arise by deleting suitable hyperplanes that remain inside the same class.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
A decomposition of configurations in a class K into two smaller ones in K, resembling the rows of Pascal's triangle, is obtained by choosing a hyperplane that lies in K such that removing it yields another configuration still belonging to K. This property holds for the class studied in prior work and for two further natural classes of configurations presented here.
What carries the argument
Suitable hyperplanes in a class K of configurations: hyperplanes that belong to K and whose deletion produces another configuration in K.
If this is right
- The decomposition can be iterated inside each class, producing a triangular array of configurations.
- At least three distinct natural classes satisfy the closure property under suitable hyperplane deletion.
- The same mechanism accounts for the earlier construction given in referenced work.
- Further classes can be tested for the property by checking whether they contain hyperplanes closed in this way.
Where Pith is reading between the lines
- The closure condition may serve as a definition that singles out exactly those classes for which Pascal-like decompositions exist.
- Computational enumeration of small configurations could locate additional classes satisfying the hyperplane condition.
- The approach suggests examining whether the same hyperplane selection yields analogous decompositions in non-binomial incidence structures.
Load-bearing premise
Natural classes of configurations exist in which at least one hyperplane can be chosen so that both it and the result after its deletion stay inside the class.
What would settle it
A concrete class K presented as admitting such hyperplanes for which every candidate hyperplane either lies outside K or leaves a configuration outside K after deletion.
read the original abstract
An elegant procedure which characterizes a decomposition of some class of binomial configurations into two other, resembling a definition of Pascal's Triangle, was given in \cite{gevay}. In essence, this construction was already presented in \cite{perspect}. We show that such a procedure is a result of fixing in configurations in some class $\mathcal K$ suitable hyperplanes which both: are in this class, and deleting such a hyperplane results in a configuration in this class. By a way of example we show two more (added to that of \cite{gevay}) natural classes of such configurations, discuss some other, and propose some open questions that seem also natural in this context.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper claims that the decomposition procedure for certain classes of binomial configurations (resembling Pascal's triangle) introduced in Gevay is equivalent to selecting hyperplanes that lie in a class K and whose deletion also yields a member of K. It exhibits two additional natural classes K with these closure properties (beyond the one in the cited work), discusses further candidates, and poses open questions about the framework.
Significance. The reframing supplies a uniform, closure-based explanation for the decompositions and supplies concrete new examples of admissible classes K. Because the argument is primarily definitional and example-driven rather than dependent on a single technical lemma, the contribution lies in conceptual unification and the explicit construction of further instances; the open questions are natural and may guide subsequent classification work in combinatorial configuration theory.
minor comments (3)
- [Abstract] Abstract: the phrase 'by a way of example' should read 'by way of example'.
- [Introduction] The manuscript should include a brief, self-contained definition or reference to the precise notion of 'binomial configuration' used throughout, to make the closure properties immediately verifiable without consulting the cited papers.
- [Section 3 (or whichever section introduces the examples)] When presenting the two new classes K, state explicitly which axioms or incidence properties are preserved under the hyperplane deletion operation, citing the relevant equations or definitions.
Simulated Author's Rebuttal
We thank the referee for the positive report, accurate summary of the manuscript's contributions, and recommendation of minor revision. The referee correctly identifies the core reframing via hyperplane selection with closure properties under deletion, the two new classes K, and the open questions posed.
Circularity Check
No significant circularity identified
full rationale
The paper reinterprets the decomposition procedure from the independently cited works [gevay] and [perspect] as equivalent to selecting hyperplanes that remain inside a class K under deletion. It supplies two additional explicit classes K satisfying the stated closure properties and poses open questions. No load-bearing step reduces to a self-citation, fitted parameter, or definitional renaming; the argument is explicitly example-driven and definitional rather than derived from its own inputs.
Axiom & Free-Parameter Ledger
axioms (1)
- domain assumption The class K of configurations is closed under the hyperplane selection and deletion operation.
Lean theorems connected to this paper
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IndisputableMonolith/Foundation/ArithmeticFromLogic.leanLogicNat recovery; embed_strictMono_of_one_lt unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
B(k, m) = B(k, m − 1) ⋊ ∞ B(k − 1, m)
What do these tags mean?
- matches
- The paper's claim is directly supported by a theorem in the formal canon.
- supports
- The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
- extends
- The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
- uses
- The paper appears to rely on the theorem as machinery.
- contradicts
- The paper's claim conflicts with a theorem or certificate in the canon.
- unclear
- Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.
Reference graph
Works this paper leans on
-
[1]
Berger (1987) Affine-projective relationship: applications , [In:] Berger M
M. Berger (1987) Affine-projective relationship: applications , [In:] Berger M. (eds) Geometry I, Universitext. Springer, Berlin, Heidelb erg (1987), Chapter 5, 111–121
work page 1987
-
[2]
A. M. Cohen, E. E. Shult Affine polar spaces , Geom. Dedicata 35 (1990), 43–76
work page 1990
-
[3]
H. S. M. Coxeter , Self-dual configurations and regular graphs , Bull. Amer. Math. Soc. 56(1950), 413–455
work page 1950
-
[4]
G ´ evay, Pascal’s triangle of configurations , [in:] Marston D
G. G ´ evay, Pascal’s triangle of configurations , [in:] Marston D. E. Conder, Antoine Deza, Asia Ivi´ c Weiss(ed’s), Discrete Geometry and Symmetry , GSC
-
[5]
Springer, Cham (2018), 181–199, DOI:10.1007/978-3-319-78434-2 10
Springer Proceedings in Mathematics & Statistics, vo l 234. Springer, Cham (2018), 181–199, DOI:10.1007/978-3-319-78434-2 10
-
[6]
M. Ch. Klin, R. P ¨oschel, K. Rosenbaum , Angewandte Algebra f¨ ur Math- ematiker und Informatiker , VEB Deutcher Verlag der Wissenschaften, Berlin 1988
work page 1988
-
[7]
Levi , Geometrische Konfigurationen, Leipzig, S
F. Levi , Geometrische Konfigurationen, Leipzig, S. Hirzel (1929)
work page 1929
-
[8]
K. Petelczyc, M. ˙Zynel, Affinization of Segre products of partial linear spaces, Bull. Iranian Math. Soc. 43(2017), no. 5, 1101–1126
work page 2017
-
[9]
Binomial partial Steiner triple systems with complete graphs: structural problems
K. Petelczyc, M. Pra ˙zmowska, K. Pra ˙zmowski, Binomial partial Steiner triple systems with complete graphs: structural problems , 2015, arXiv:1508.05974
work page internal anchor Pith review Pith/arXiv arXiv 2015
-
[10]
K. Petelczyc, M. Pra ˙zmowska, 10 3-configurations and projective realizabil- ity of multiplied configurations , Des. Codes Cryptogr. 51, no. 1 (2009), 45–54
work page 2009
-
[11]
M. Pra ˙zmowska, Multiple perspectives and generalizations of the Desargue s configuration, Demonstratio Math. 39 (2006), no. 4, 887–906
work page 2006
-
[12]
M. Pra ˙zmowska, K. Pra ˙zmowski, Combinatorial Veronese structures, their geometry, and problems of embeddability , Results Math. 51 (2008), 275–308
work page 2008
-
[13]
M. Pra ˙zmowska, On some regular multi-veblen configurations, the geometry of combinatorial quasi Grassmannians , Demonstratio Math. 42 (2009), no.2 387–402
work page 2009
-
[14]
M. Saniga, F. Holweck, P. Pracna , From Cayley-Dickson Alge- bras to Combinatorial Grassmannians , Mathematics 2015 3(4), 1192–1221, DOI:10.3390/math3041192
-
[15]
W. Szmielew , On n-ary equivalence relations in algebra and their applicatio ns to geometry , Warsaw, Dissertationes PAS (1981)
work page 1981
-
[16]
O. Veblen, J. W. Young , Projective Geometry , University of Michigan Library (January 1, 1910) Authors’ address: Krzysztof Pra˙ zmowski, Institute of Mathematics, University of Bia/suppress lystok K. Cio/suppress lkowskiego 1M, 15-245 Bia/suppress lystok, Poland e-mail: krzypraz@math.uwb.edu.pl,
work page 1910
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