Recognition: 3 theorem links
· Lean TheoremSolving one-sided linear systems over symmetrized and supertropical semiring
Pith reviewed 2026-05-08 18:33 UTC · model grok-4.3
The pith
One-sided linear systems over symmetrized and supertropical semirings can be solved by first finding the greatest solution in polynomial time and then searching for minimal solutions.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
The central claim is that the approach of first computing the greatest solution to Ax equals b in polynomial time and then finding minimal solutions extends directly to one-sided linear systems over symmetrized and supertropical semirings. The extension is developed without introducing fundamentally new obstacles, and the findings are used to discuss implications for tropical cryptography.
What carries the argument
The two-step solution procedure of polynomial-time greatest-solution computation followed by minimal-solution search.
If this is right
- Greatest solutions to Ax equals b remain computable in polynomial time over both extended semirings.
- Minimal solutions can be located by adapting the search procedures from the tropical case.
- The same complexity profile holds, so the systems stay tractable in the same way.
- The results directly inform the design or analysis of protocols in tropical cryptography.
Where Pith is reading between the lines
- The same two-step method might generalize to further semiring extensions not covered in the paper.
- Concrete implementations on example systems could show whether runtimes differ noticeably in cryptographic applications.
- Related problems in signed or uncertain optimization might admit similar reductions to greatest-then-minimal search.
Load-bearing premise
The methods for finding the greatest solution and then minimal solutions transfer to symmetrized and supertropical semirings without new computational obstacles or different techniques.
What would settle it
A concrete linear system Ax equals b over the supertropical semiring for which no greatest solution can be computed in polynomial time.
read the original abstract
One-sided linear systems of the form ``$Ax=b$'' are well-known and extensively studied over the tropical (max-plus) semiring and wide classes of related idempotent semirings. The usual approach is to first find the greatest solution to such system in polynomial time and then to solve a much harder problem of finding all minimal solutions. We develop an extension of this approach to the same systems over two well-known extensions of the tropical semiring: symmetrized and supertropical, and discuss the implications of our findings for the tropical cryptography.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper extends the standard approach for solving one-sided linear systems Ax=b over the tropical semiring to symmetrized and supertropical semirings. It shows that the greatest solution remains computable in polynomial time via a modified closure operator respecting the symmetrized sign structure and supertropical ghost ideal (both residuated), while minimal solutions are enumerated via covering-set search with only local adjustments to the dominance relation, without new exponential blow-up or undecidability. A qualitative discussion addresses implications for tropical cryptography.
Significance. If the extensions hold, the work unifies computational techniques across these idempotent semiring extensions while preserving key efficiency properties, which is valuable for tropical algebra and its applications. The explicit confirmation that residuation carries over and that the covering-set method adapts locally strengthens the foundation for further algorithmic development; the cryptography remarks usefully flag potential shifts in hardness assumptions even if they remain qualitative.
minor comments (3)
- Abstract: the phrase 'discuss the implications of our findings for the tropical cryptography' is vague; a single sentence indicating whether the new semirings strengthen or weaken the underlying hardness assumption would improve clarity.
- Section describing the symmetrized case: the modified closure operator is stated to respect the sign structure, but an explicit verification that the resulting greatest solution still satisfies the original system (analogous to the tropical proof) would help readers confirm the adaptation.
- Enumeration of minimal solutions: while local adjustments to the dominance relation are mentioned, including a small concrete example contrasting the tropical and supertropical dominance checks would make the 'no new exponential blow-up' claim more tangible.
Simulated Author's Rebuttal
We thank the referee for the positive summary, significance assessment, and recommendation of minor revision. No specific major comments were raised in the report, so our response focuses on confirming the overall alignment with the manuscript's contributions and noting that we will incorporate any minor editorial suggestions in the revised version.
Circularity Check
No significant circularity detected
full rationale
The paper extends the standard two-step procedure (polynomial-time greatest solution via closure operator, followed by enumeration of minimal solutions) from tropical semirings to symmetrized and supertropical variants by adapting the residuation and dominance relations to the new sign/ghost structures. These adaptations are presented as direct consequences of the algebraic definitions of the extended semirings rather than being fitted to data or reduced to prior self-citations. No equations are shown to be equivalent by construction to their inputs, no parameters are fitted and then relabeled as predictions, and the cryptography remarks remain qualitative without relying on unproven transfer of complexity results. The derivation chain is therefore self-contained against the external algebraic properties of the semirings.
Axiom & Free-Parameter Ledger
Lean theorems connected to this paper
-
Foundation/Atomicity.leanatomic_tick / exists_sequential_schedule (only superficial overlap: both manipulate finite covers/orderings, but for unrelated purposes) unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
The usual approach is to first find the greatest solution... and then to solve a much harder problem of finding all minimal solutions... equivalent to the hypergraph transversal enumeration problem.
-
Cost/FunctionalEquation.leanwashburn_uniqueness_aczel (RS J=½(x+x⁻¹)−1 is forced by reciprocal symmetry; supertropical tangible/ghost has no x↔x⁻¹ analog or J-positivity/φ fixed point) unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
The supertropical semiring... distinguishes tangible and ghost elements and uses the ghost surpass relation to recover some classical linear algebra features.
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]
- [2]
-
[3]
Alhussaini and S
S. Alhussaini and S. Sergeev. Cryptanalysis of multi-party key exchange protocols over a modified supertropical semiring. Cryptology ePrint Archive, Paper 2025/2062, 2025
2025
-
[4]
Baccelli, G
F.L. Baccelli, G. Cohen, G.J. Olsder, and J.P. Quadrat.Synchronization and Linearity: An Algebra for Discrete Event Systems. John Wiley & Sons Ltd, Chichester, UK, 1992
1992
-
[5]
Efficiently enumerating hitting sets of hypergraphs arising in data profiling.Journal of Computer and System Sciences, 124:192–213, 2022
T.Bläsius, T.Friedrich, J.Lischeid, K.Meeks, andM.Schirneck. Efficiently enumerating hitting sets of hypergraphs arising in data profiling.Journal of Computer and System Sciences, 124:192–213, 2022
2022
-
[6]
Butkovič.Max-linear Systems: Theory and Algorithms
P. Butkovič.Max-linear Systems: Theory and Algorithms. Springer, Lon- don, 2010. 30
2010
-
[7]
Cuninghame-Green.Minimax algebra, volume 166 ofLecture Notes in Economics and Mathematical Systems
R.A. Cuninghame-Green.Minimax algebra, volume 166 ofLecture Notes in Economics and Mathematical Systems. Springer, Berlin, Heidelberg, 1979
1979
-
[8]
Di Nola, W
A. Di Nola, W. Pedrycz, and S. Sessa. Fuzzy relation equations under LSC and USCt-norms and their Boolean solutions.Stochastica, 11(2-3), 1987
1987
-
[9]
Elbassioni
K. Elbassioni. A note on systems with max–min and max-product con- straints.Fuzzy Sets and Systems, 159(17):2272–2277, 2008. Theme: Fuzzy Relations
2008
-
[10]
S. Elt. Cryptography in symmetrised tropical algebra. Master’s thesis, Uni- versity of Birmingham, School of Mathematics, Birmingham, UK, March 2024
2024
-
[11]
Gaubert.Théorie des systèmes linéaires dans les dioïdes
S. Gaubert.Théorie des systèmes linéaires dans les dioïdes. Thèse, École des Mines de Paris, July 1992
1992
-
[12]
Grigoriev and V
D. Grigoriev and V. Shpilrain. Tropical cryptography.Communications in Algebra, 42:2624 – 2632, 2013
2013
-
[13]
Izhakian and L
Z. Izhakian and L. Rowen. Supertropical linear algebra.Pacific Journal of Mathematics, 266(1):43–75, 2013
2013
-
[14]
Karp.Reducibility among Combinatorial Problems, pages 85–103
R. Karp.Reducibility among Combinatorial Problems, pages 85–103. Springer US, Boston, MA, 1972
1972
-
[15]
Kotov and A
M. Kotov and A. Ushakov. Analysis of a key exchange protocol based on tropical matrix algebra.Journal of Mathematical Cryptology, 12(3):137– 141, 2018
2018
-
[16]
A. V. Markovskii. Solution of fuzzy equations with max-product compo- sition in inverse control and decision making problems.Automation and Remote Control, 65(9):1486–1495, Sep 2004
2004
-
[17]
Otero Sánchez, D
Á. Otero Sánchez, D. Camazón Portela, and J.A. López-Ramos. On the solutions of linear systems over additively idempotent semirings.Mathe- matics, 12(18), 2024
2024
-
[18]
Ponmaheshkumar, J
R. Ponmaheshkumar, J. Ramalingham, and R. Perumal. Multi-party key exchange scheme based on super-tropical semiring.Cryptologia, 2025. pub- lished online
2025
-
[19]
E. Stickel. A new method for exchanging secret keys. InThird Interna- tional Conference on Information Technology and Applications (ICITA’05), volume 2, pages 426–430, 2005
2005
-
[20]
Vorobyev
N.N. Vorobyev. Extremal algebra of positive matrices.Elektron. Informa- tionsverarbeitung und Kybernetik, 3(1):39–72, 1967. in Russian. 31
1967
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.