Results 1 to 10 of about 19,622 (256)
Piecewise testable tree languages [PDF]
Logical Methods in Computer Science, 2012 This paper presents a decidable characterization of tree languages that can be defined by a boolean combination of Sigma_1 sentences. This is a tree extension of the Simon theorem, which says that a string language can be defined by a boolean combination
Mikołaj Bojańczyk +2 more
doaj +5 more sources
Demonstratio Mathematica, 2013 Abstract A tree language of a fixed type τ is any set of terms of type τ. We consider here a binary operation + n on the set Wτ (Xn ) of all n-ary terms of type τ, which results in semigroup (Wτ (Xn ...
S L Wismath
exaly +3 more sources
Tree algebras and varieties of tree languages
Theoretical Computer Science, 2007 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Saeed Salehi
exaly +3 more sources
Disentangling complex language contact and admixture in the broad Gansu-Qinghai region [PDF]
Fundamental ResearchLanguage evolution in the Gansu-Qinghai (GQ) region provides a key perspective for understanding cultural development along the eastern Silk Road. Previous genetic and archaeological studies have revealed complex, multi-ethnic interactions in this region,
Hongye Jin +7 more
doaj +2 more sources
Positive varieties of tree languages
Theoretical Computer Science, 2005 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Saeed Salehi, Tatjana Petković
exaly +2 more sources
General varieties of tree languages
Theoretical Computer Science, 1998 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Magnus Steinby
exaly +2 more sources
Ambiguity Hierarchy of Regular Infinite Tree Languages [PDF]
Logical Methods in Computer Science, 2021 An automaton is unambiguous if for every input it has at most one accepting computation. An automaton is k-ambiguous (for k > 0) if for every input it has at most k accepting computations. An automaton is boundedly ambiguous if it is k-ambiguous for some
Alexander Rabinovich, Doron Tiferet
doaj +1 more source
Aperiodicity, Star-freeness, and First-order Logic Definability of Operator Precedence Languages [PDF]
Logical Methods in Computer Science, 2023 A classic result in formal language theory is the equivalence among non-counting, or aperiodic, regular languages, and languages defined through star-free regular expressions, or first-order logic.
Dino Mandrioli +2 more
doaj +1 more source
Phylogenetic trees: Grammar versus vocabulary
Russian Journal of Linguistics, 2022 Traditionally, genealogical relationships between languages are established on the basis of phonetic and lexical data. The question whether genealogical relationships among languages can be defined based on grammatical data remains unanswered.
Vladimir N. Polyakov +2 more
doaj +1 more source
E-unification by means of tree tuple synchronized grammars [PDF]
Discrete Mathematics & Theoretical Computer Science, 1997 The goal of this paper is both to give an E-unification procedure that always terminates, and to decide unifiability. For this, we assume that the equational theory is specified by a confluent and constructor-based rewrite system, and that four ...
Sébastien Limet, Pierre Réty
doaj +1 more source