Information and Computation最新文献

{"title":"Preface to special issue MFCS 2023","authors":"Jérôme Leroux, David Peleg","doi":"10.1016/j.ic.2025.105325","DOIUrl":"10.1016/j.ic.2025.105325","url":null,"abstract":"","PeriodicalId":54985,"journal":{"name":"Information and Computation","volume":"306 ","pages":"Article 105325"},"PeriodicalIF":0.8,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144514104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parikh one-counter automata","authors":"Michaël Cadilhac ,&nbsp;Arka Ghosh ,&nbsp;Guillermo A. Pérez ,&nbsp;Ritam Raha","doi":"10.1016/j.ic.2025.105322","DOIUrl":"10.1016/j.ic.2025.105322","url":null,"abstract":"<div><div>Counting abilities in finite automata are traditionally provided by two orthogonal extensions: adding a single counter that can be tested for zeroness at any point, or adding <span><math><mi>Z</mi></math></span>-valued counters that are tested for equality only at the end of runs. In this paper, finite automata extended with both types of counters are introduced. They are called Parikh One-Counter Automata (POCA): the “Parikh” part referring to the evaluation of counters at the end of runs, and the “One-Counter” part to the single counter that can be tested during runs.</div><div>Their expressiveness, in the deterministic and nondeterministic variants, is investigated; it is shown in particular that there are deterministic POCA languages that cannot be expressed without nondeterminism in the original models. The natural decision problems are also studied; strikingly, most of them are no harder than in the original models. A parametric version of nonemptiness is also considered.</div></div>","PeriodicalId":54985,"journal":{"name":"Information and Computation","volume":"306 ","pages":"Article 105322"},"PeriodicalIF":0.8,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144313099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The longest subsequence-duplicated subsequence and related problems","authors":"Manuel Lafond ,&nbsp;Wenfeng Lai ,&nbsp;Adiesha Liyanage ,&nbsp;Binhai Zhu","doi":"10.1016/j.ic.2025.105313","DOIUrl":"10.1016/j.ic.2025.105313","url":null,"abstract":"<div><div>Motivated by computing duplication patterns in sequences, a new fundamental problem called the longest subsequence-duplicated subsequence (LSDS) is proposed. Given a sequence <em>S</em> of length <em>n</em>, a subsequence-duplicated subsequence is a subsequence of <em>S</em> in the form of <span><math><msubsup><mrow><mi>x</mi></mrow><mrow><mn>1</mn></mrow><mrow><msub><mrow><mi>d</mi></mrow><mrow><mn>1</mn></mrow></msub></mrow></msubsup><msubsup><mrow><mi>x</mi></mrow><mrow><mn>2</mn></mrow><mrow><msub><mrow><mi>d</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></msubsup><mo>⋯</mo><msubsup><mrow><mi>x</mi></mrow><mrow><mi>k</mi></mrow><mrow><msub><mrow><mi>d</mi></mrow><mrow><mi>k</mi></mrow></msub></mrow></msubsup></math></span> with <span><math><msub><mrow><mi>x</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span> being a subsequence of <em>S</em>, <span><math><msub><mrow><mi>x</mi></mrow><mrow><mi>j</mi></mrow></msub><mo>≠</mo><msub><mrow><mi>x</mi></mrow><mrow><mi>j</mi><mo>+</mo><mn>1</mn></mrow></msub></math></span> and <span><math><msub><mrow><mi>d</mi></mrow><mrow><mi>i</mi></mrow></msub><mo>≥</mo><mn>2</mn></math></span> for all <em>i</em> in <span><math><mo>[</mo><mi>k</mi><mo>]</mo></math></span> and <em>j</em> in <span><math><mo>[</mo><mi>k</mi><mo>−</mo><mn>1</mn><mo>]</mo></math></span>. We first present an <span><math><mi>O</mi><mo>(</mo><msup><mrow><mi>n</mi></mrow><mrow><mn>6</mn></mrow></msup><mo>)</mo></math></span> time algorithm to compute the longest cubic subsequences of all the <span><math><mi>O</mi><mo>(</mo><msup><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>)</mo></math></span> substrings of <em>S</em>, improving the trivial <span><math><mi>O</mi><mo>(</mo><msup><mrow><mi>n</mi></mrow><mrow><mn>7</mn></mrow></msup><mo>)</mo></math></span> bound. Then, an <span><math><mi>O</mi><mo>(</mo><msup><mrow><mi>n</mi></mrow><mrow><mn>6</mn></mrow></msup><mo>)</mo></math></span> time algorithm for computing the longest subsequence-duplicated subsequence (LSDS) of <em>S</em> is obtained. Finally we focus on two variants of this problem. We first consider the constrained version when Σ is unbounded, each letter appears in <em>S</em> at most <em>d</em> times and all the letters in Σ must appear in the solution. We show that the problem is NP-hard for <span><math><mi>d</mi><mo>=</mo><mn>4</mn></math></span>, via a reduction from a special version of SAT (which is obtained from 3-COLORING). We then show that when each letter appears in <em>S</em> at most <span><math><mi>d</mi><mo>=</mo><mn>3</mn></math></span> times, then the problem is solvable in <span><math><mi>O</mi><mo>(</mo><msup><mrow><mi>n</mi></mrow><mrow><mn>4</mn></mrow></msup><mo>)</mo></math></span> time.</div></div>","PeriodicalId":54985,"journal":{"name":"Information and Computation","volume":"306 ","pages":"Article 105313"},"PeriodicalIF":0.8,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144239846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probabilistic input-driven pushdown automata","authors":"Alex Rose ,&nbsp;Alexander Okhotin","doi":"10.1016/j.ic.2025.105312","DOIUrl":"10.1016/j.ic.2025.105312","url":null,"abstract":"<div><div>A probabilistic variant of input-driven pushdown automata (IDPDA), also known as visibly pushdown automata, is introduced. It is proved that these automata can be determinized: an <em>n</em>-state probabilistic IDPDA that accepts each string with probability at least <span><math><mi>λ</mi><mo>+</mo><mi>δ</mi></math></span> or at most <span><math><mi>λ</mi><mo>−</mo><mi>δ</mi></math></span>, for some isolated cut-point <span><math><mi>λ</mi><mo>∈</mo><mo>[</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>]</mo></math></span> with <span><math><mi>δ</mi><mo>&gt;</mo><mn>0</mn></math></span>, is transformed to a deterministic IDPDA recognizing the same language, with at most <span><math><msup><mrow><mo>(</mo><mn>1</mn><mo>+</mo><mfrac><mrow><mn>1</mn></mrow><mrow><mi>δ</mi></mrow></mfrac><mo>)</mo></mrow><mrow><msup><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>−</mo><mi>n</mi></mrow></msup></math></span> states and at most <span><math><mo>|</mo><msub><mrow><mi>Σ</mi></mrow><mrow><mo>+</mo><mn>1</mn></mrow></msub><mo>|</mo><mo>⋅</mo><msup><mrow><mo>(</mo><mn>1</mn><mo>+</mo><mfrac><mrow><mn>1</mn></mrow><mrow><mi>δ</mi></mrow></mfrac><mo>)</mo></mrow><mrow><msup><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>−</mo><mi>n</mi></mrow></msup></math></span> stack symbols, where <span><math><msub><mrow><mi>Σ</mi></mrow><mrow><mo>+</mo><mn>1</mn></mrow></msub></math></span> is the set of left bracket symbols in the alphabet. An asymptotically close lower bound is provided: for infinitely many <em>n</em>, there is a probabilistic IDPDA with <span><math><mn>2</mn><mi>n</mi><mo>+</mo><mn>3</mn></math></span> states and <em>n</em> stack symbols, and with <span><math><mi>δ</mi><mo>=</mo><mfrac><mrow><mn>1</mn></mrow><mrow><mn>270</mn><mi>n</mi></mrow></mfrac></math></span>, such that every equivalent deterministic IDPDA needs at least <span><math><msup><mrow><mn>7</mn></mrow><mrow><msup><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>/</mo><mn>14</mn></mrow></msup></math></span> states and at least <em>n</em> stack symbols. A few special cases of automata with reduced determinization complexity are identified.</div></div>","PeriodicalId":54985,"journal":{"name":"Information and Computation","volume":"305 ","pages":"Article 105312"},"PeriodicalIF":0.8,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144134522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The generalized constrained longest common subsequence in the run-length encoded format","authors":"En-An Song ,&nbsp;Chang-Biau Yang ,&nbsp;Kuo-Tsung Tseng","doi":"10.1016/j.ic.2025.105311","DOIUrl":"10.1016/j.ic.2025.105311","url":null,"abstract":"<div><div>The longest common subsequence (LCS) is commonly used as a similarity measurement between two given sequences (strings). Several variants of the LCS problem have been developed. The generalized constrained LCS (CLCS) problems have four variants: substring exclusion (STR-EC-LCS), substring inclusion, subsequence exclusion and subsequence inclusion. In the STR-EC-LCS problem, a given constraint string is excluded as a substring from the answer. For the STR-EC-LCS problem with run-length encoded (RLE) strings, we are given two strings <em>X</em> and <em>Y</em>, along with a constraint string <em>P</em>, consisting of <em>M</em>, <em>N</em> and <em>R</em> runs, respectively. In their plain (non-RLE) representations, the lengths of these strings are <span><math><mo>|</mo><mi>X</mi><mo>|</mo><mo>=</mo><mi>m</mi></math></span>, <span><math><mo>|</mo><mi>Y</mi><mo>|</mo><mo>=</mo><mi>n</mi></math></span> and <span><math><mo>|</mo><mi>P</mi><mo>|</mo><mo>=</mo><mi>r</mi></math></span>. We combine the state transition with the dynamic programming approach to solve the STR-EC-LCS problem with RLE strings. The time complexity of our algorithm is O<span><math><mo>(</mo><mi>r</mi><mo>(</mo><mi>M</mi><mi>n</mi><mo>+</mo><mi>m</mi><mi>N</mi><mo>)</mo><mo>)</mo></math></span>. The previous algorithm for STR-EC-LCS without RLE has a time complexity of O<span><math><mo>(</mo><mi>m</mi><mi>n</mi><mi>r</mi><mo>)</mo></math></span>. Since <span><math><mi>M</mi><mo>≤</mo><mi>m</mi></math></span> and <span><math><mi>N</mi><mo>≤</mo><mi>n</mi></math></span>, our algorithm improves the previous algorithm in time complexity. Additionally, our algorithm, which is based on state transitions, is universal and can be applied to the other three variants of the generalized constrained LCS problem with the same complexity.</div></div>","PeriodicalId":54985,"journal":{"name":"Information and Computation","volume":"305 ","pages":"Article 105311"},"PeriodicalIF":0.8,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144116409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Further results on the Hunters and Rabbit game through monotonicity","authors":"Thomas Dissaux ,&nbsp;Foivos Fioravantes ,&nbsp;Harmender Gahlawat ,&nbsp;Nicolas Nisse","doi":"10.1016/j.ic.2025.105302","DOIUrl":"10.1016/j.ic.2025.105302","url":null,"abstract":"<div><div>The <span>Hunters and Rabbit</span> game is played on a graph <em>G</em> where the Hunter player shoots at <em>k</em> vertices in every round while the Rabbit player occupies an unknown vertex and, if not shot, must move to a neighbouring vertex. The Rabbit player wins if and only if it is not shot indefinitely. The hunter number <span><math><mi>h</mi><mo>(</mo><mi>G</mi><mo>)</mo></math></span> of a graph <em>G</em> is the minimum <em>k</em> such that the Hunter player has a winning strategy. We propose a notion of monotonicity, embodied in the monotone hunter number <span><math><mi>m</mi><mi>h</mi><mo>(</mo><mi>G</mi><mo>)</mo></math></span>, for this game imposing that a vertex that has already been shot “must not host the rabbit anymore”.</div><div>We show that <span><math><mi>p</mi><mi>w</mi><mo>(</mo><mi>G</mi><mo>)</mo><mo>≤</mo><mi>m</mi><mi>h</mi><mo>(</mo><mi>G</mi><mo>)</mo><mo>≤</mo><mi>p</mi><mi>w</mi><mo>(</mo><mi>G</mi><mo>)</mo><mo>+</mo><mn>1</mn></math></span> for any graph <em>G</em> with pathwidth <span><math><mi>p</mi><mi>w</mi><mo>(</mo><mi>G</mi><mo>)</mo></math></span>, implying that computing, or even approximating, <span><math><mi>m</mi><mi>h</mi><mo>(</mo><mi>G</mi><mo>)</mo></math></span> is <span>NP</span>-hard. Then, we show that <span><math><mi>m</mi><mi>h</mi><mo>(</mo><mi>G</mi><mo>)</mo></math></span> can be computed in polynomial time in split graphs, interval graphs, cographs and trees. These results go through structural characterisations which relate the monotone hunter number with the pathwidth. In all these cases, we either specify the hunter number or show that there may be an arbitrary gap between <em>h</em> and <em>mh</em>, i.e., that monotonicity does not help. In particular, for every <span><math><mi>k</mi><mo>≥</mo><mn>3</mn></math></span>, we construct a tree <em>T</em> with <span><math><mi>h</mi><mo>(</mo><mi>T</mi><mo>)</mo><mo>=</mo><mn>2</mn></math></span> and <span><math><mi>m</mi><mi>h</mi><mo>(</mo><mi>T</mi><mo>)</mo><mo>=</mo><mi>k</mi></math></span>. We conclude by proving that computing <em>h</em> (resp., <em>mh</em>) is <span><math><mi>FPT</mi></math></span> parameterised by the vertex cover number.</div></div>","PeriodicalId":54985,"journal":{"name":"Information and Computation","volume":"305 ","pages":"Article 105302"},"PeriodicalIF":0.8,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143922333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measuring the expressive power of practical regular expressions by classical stacking automata models","authors":"Taisei Nogami ,&nbsp;Tachio Terauchi","doi":"10.1016/j.ic.2025.105303","DOIUrl":"10.1016/j.ic.2025.105303","url":null,"abstract":"<div><div>A <em>rewb</em> is a regular expression extended with a feature called backreference. It is broadly known that backreference is a practical extension of regular expressions, and is supported by most modern regular expression engines, such as those in the standard libraries of Java, Python, and more. Meanwhile, <em>indexed languages</em> are the languages generated by indexed grammars, a formal grammar class proposed by A.V. Aho. We show that these two models' expressive powers are related in the following way: every language described by a rewb is an indexed language. As the smallest formal grammar class previously known to contain rewbs is the class of context sensitive languages, our result strictly improves the known upper-bound. Moreover, we prove the following four claims: (1) there exists a rewb whose language does not belong to the class of stack languages, which is a proper subclass of indexed languages, (2) the language described by a rewb without a captured reference is in the class of nonerasing stack languages, which is a proper subclass of stack languages, (3) there exists a rewb that describes a stack language but not a nonerasing stack language, and (4) a rewb extended with another practical extension called lookaheads can describe a non-indexed language. Finally, we show that the hierarchy investigated in a prior study, which separates the expressive power of rewbs by the notion of nested levels, is within the class of nonerasing stack languages.</div></div>","PeriodicalId":54985,"journal":{"name":"Information and Computation","volume":"305 ","pages":"Article 105303"},"PeriodicalIF":0.8,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143922097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chained time lock puzzle with small puzzle size","authors":"Ramakant Kumar,&nbsp;Sahadeo Padhye","doi":"10.1016/j.ic.2025.105301","DOIUrl":"10.1016/j.ic.2025.105301","url":null,"abstract":"<div><div>A time lock puzzle (TLP) is an interesting cryptographic primitive used to lock messages for a limited time period. After the desired time interval, the puzzle solver can know the message. Chained time lock puzzle (C-TLP) is multi instance time lock puzzle where the solution of any instance depends on the previous instance. In this paper, we design a C-TLP with security relying on the integer factorization problem (IFP). The size of the output puzzle is smaller than the size in the existing C-TLPs.</div></div>","PeriodicalId":54985,"journal":{"name":"Information and Computation","volume":"304 ","pages":"Article 105301"},"PeriodicalIF":0.8,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143870089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modules and PQ-trees in Robinson spaces","authors":"M. Carmona ,&nbsp;V. Chepoi ,&nbsp;G. Naves ,&nbsp;P. Préa","doi":"10.1016/j.ic.2025.105300","DOIUrl":"10.1016/j.ic.2025.105300","url":null,"abstract":"<div><div>A Robinson space is a dissimilarity space <span><math><mo>(</mo><mi>X</mi><mo>,</mo><mi>d</mi><mo>)</mo></math></span> on <em>n</em> points for which there exists a compatible order, <em>i.e.</em> a total order &lt; on <em>X</em> such that <span><math><mi>x</mi><mo>&lt;</mo><mi>y</mi><mo>&lt;</mo><mi>z</mi></math></span> implies that <span><math><mi>d</mi><mo>(</mo><mi>x</mi><mo>,</mo><mi>y</mi><mo>)</mo><mo>≤</mo><mi>d</mi><mo>(</mo><mi>x</mi><mo>,</mo><mi>z</mi><mo>)</mo></math></span> and <span><math><mi>d</mi><mo>(</mo><mi>y</mi><mo>,</mo><mi>z</mi><mo>)</mo><mo>≤</mo><mi>d</mi><mo>(</mo><mi>x</mi><mo>,</mo><mi>z</mi><mo>)</mo></math></span>. Recognizing whether a dissimilarity space is Robinson has numerous applications in seriation and classification. The set of all compatible orders of a Robinson space can be succintly represented by a PQ-tree, a classical data structure introduced by Booth and Lueker. An mmodule is a subset <em>M</em> of <em>X</em> which is not distinguishable from the outside of <em>M</em>, <em>i.e.</em> the distances from any point of <span><math><mi>X</mi><mo>∖</mo><mi>M</mi></math></span> to all points of <em>M</em> are the same. The hierarchical structure of mmodules can also be represented by a tree: the mmodule-tree of a dissimilarity space <span><math><mo>(</mo><mi>X</mi><mo>,</mo><mi>d</mi><mo>)</mo></math></span>.</div><div>In this paper, we establish correspondences between the PQ-trees and the mmodule-trees of Robinson spaces. More precisely, we show how to construct the mmodule-tree of a Robinson dissimilarity from its PQ-tree and <em>vice versa</em>. To establish this translation, we introduce the notions of <em>δ</em>-graph <span><math><msub><mrow><mi>G</mi></mrow><mrow><mover><mrow><mi>δ</mi></mrow><mo>‾</mo></mover></mrow></msub></math></span> of a Robinson space and of <em>δ</em>-mmodules, the connected components of <span><math><msub><mrow><mi>G</mi></mrow><mrow><mover><mrow><mi>δ</mi></mrow><mo>‾</mo></mover></mrow></msub></math></span>. It also involves the dendrogram of the subdominant ultrametric of <em>d</em>. All these results also lead to optimal <span><math><mi>O</mi><mo>(</mo><msup><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>)</mo></math></span> time algorithms for constructing the PQ-tree and the mmodule tree of Robinson spaces.</div></div>","PeriodicalId":54985,"journal":{"name":"Information and Computation","volume":"304 ","pages":"Article 105300"},"PeriodicalIF":0.8,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143826082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The geometry of reachability in continuous vector addition systems with states","authors":"Shaull Almagor ,&nbsp;Arka Ghosh ,&nbsp;Tim Leys ,&nbsp;Guillermo A. Pérez","doi":"10.1016/j.ic.2025.105298","DOIUrl":"10.1016/j.ic.2025.105298","url":null,"abstract":"<div><div>We study the geometry of reachability sets of continuous vector addition systems with states (VASS). In particular we establish that they are “almost” Minkowski sums of convex cones and zonotopes generated by the vectors labelling the transitions of the VASS. We use the latter to prove that short so-called linear path schemes suffice as witnesses of reachability in continuous VASS. Then, we give new polynomial-time algorithms for the reachability problem for linear path schemes. Finally, we also establish that enriching the model with zero tests makes the reachability problem intractable already for linear path schemes of dimension two.</div></div>","PeriodicalId":54985,"journal":{"name":"Information and Computation","volume":"304 ","pages":"Article 105298"},"PeriodicalIF":0.8,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}