{"title":"Matching walks that are minimal with respect to edge inclusion","authors":"Victor Marsault","doi":"arxiv-2408.14048","DOIUrl":null,"url":null,"abstract":"In this paper we show that enumerating the set MM(G,R), defined below, cannot\nbe done with polynomial-delay in its input G and R, unless P=NP. R is a regular\nexpression over an alphabet $\\Sigma$, G is directed graph labeled over\n$\\Sigma$, and MM(G,R) contains walks of G. First, consider the set Match(G,R)\ncontaining all walks G labeled by a word (over $\\Sigma$) that conforms to $R$.\nIn general, M(G,R) is infinite, and MM(G,R) is the finite subset of Match(G,R)\nof the walks that are minimal according to a well-quasi-order <. It holds w<w'\nif the multiset of edges appearing in w is strictly included in the multiset of\nedges appearing in w'. Remarkably, the set MM(G,R) contains some walks that may\nbe computed in polynomial time. Hence, it is not the case that the\npreprocessing phase of any algorithm enumerating MM(G,R) must solve an NP-hard\nproblem.","PeriodicalId":501124,"journal":{"name":"arXiv - CS - Formal Languages and Automata Theory","volume":"267 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - CS - Formal Languages and Automata Theory","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2408.14048","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
In this paper we show that enumerating the set MM(G,R), defined below, cannot
be done with polynomial-delay in its input G and R, unless P=NP. R is a regular
expression over an alphabet $\Sigma$, G is directed graph labeled over
$\Sigma$, and MM(G,R) contains walks of G. First, consider the set Match(G,R)
containing all walks G labeled by a word (over $\Sigma$) that conforms to $R$.
In general, M(G,R) is infinite, and MM(G,R) is the finite subset of Match(G,R)
of the walks that are minimal according to a well-quasi-order <. It holds w