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The grammar representation of a narrowing tree for a syntactically deterministic conditional term rewriting system and a pair of terms is a regular tree grammar that generates expressions for substitutions obtained by all possible…

Logic in Computer Science · Computer Science 2019-02-25 Naoki Nishida , Yuya Maeda

We propose a new approach for universal lossless text compression, based on grammar compression. In the literature, a target string $T$ has been compressed as a context-free grammar $G$ in Chomsky normal form satisfying $L(G) = \{T\}$. Such…

Data Structures and Algorithms · Computer Science 2020-03-19 Hiroaki Naganuma , Diptarama Hendrian , Ryo Yoshinaka , Ayumi Shinohara , Naoki Kobayashi

I introduce a formalism for representing the syntax of recursively structured graph-like patterns. It does not use production rules, like a conventional graph grammar, but represents the syntactic structure in a more direct and declarative…

Formal Languages and Automata Theory · Computer Science 2025-04-25 Peter Fletcher

We study the full language of quasigeodesics in Cayley graphs, with fixed error constants. We show that, given a non-virtually-cyclic nilpotent group or Baumslag--Solitar group, and any finite generating set, such languages fail to be…

Group Theory · Mathematics 2026-04-28 Arya Saranathan

We investigate the global GRAMMAR constraint over restricted classes of context free grammars like deterministic and unambiguous context-free grammars. We show that detecting disentailment for the GRAMMAR constraint in these cases is as…

Artificial Intelligence · Computer Science 2009-06-30 George Katsirelos , Sebastian Maneth , Nina Narodytska , Toby Walsh

The literature on word-representable graphs is quite rich, and a number of variations of the original definition have been proposed over the years. We are initiating a systematic study of such variations based on formal languages. In our…

Discrete Mathematics · Computer Science 2024-11-06 Zhidan Feng , Henning Fernau , Pamela Fleischmann , Kevin Mann , Silas Cato Sacher

It has become a de-facto standard to represent words as elements of a vector space (word2vec, GloVe). While this approach is convenient, it is unnatural for language: words form a graph with a latent hierarchical structure, and this…

Computation and Language · Computer Science 2020-10-07 Max Ryabinin , Sergei Popov , Liudmila Prokhorenkova , Elena Voita

This paper introduces derivation trees for general grammars. Within these trees, it defines context-dependent pairs of nodes, corresponding to rewriting two neighboring symbols using a non context-free rule. It proves that the language…

Formal Languages and Automata Theory · Computer Science 2024-09-12 Martin Havel , Zbyněk Křivka , Alexander Meduna

We consider languages defined by signed grammars which are similar to context-free grammars except productions with signs associated to them are allowed. As a consequence, the words generated also have signs. We use the structure of the…

Formal Languages and Automata Theory · Computer Science 2023-09-19 Ömer Eğecioğlu , Benedek Nagy

This book objective is to develop an algebraization of graph grammars. Equivalently, we study graph dynamics. From the point of view of a computer scientist, graph grammars are a natural generalization of Chomsky grammars for which a purely…

Discrete Mathematics · Computer Science 2009-11-17 Pedro Pablo Perez Velasco

Multiple (simple) context-free tree grammars are investigated, where "simple" means "linear and nondeleting". Every multiple context-free tree grammar that is finitely ambiguous can be lexicalized; i.e., it can be transformed into an…

Formal Languages and Automata Theory · Computer Science 2017-07-13 Joost Engelfriet , Andreas Maletti , Sebastian Maneth

For any context-free grammar, we build a transition diagram, that is, a finite directed graph with labeled arcs, which describes the work of the grammar. This approach is new, and it is different from previously known graph models. We…

Formal Languages and Automata Theory · Computer Science 2013-05-30 Krasimir Yordzhev

This paper investigates complexity of the uniform membership problem for hyperedge replacement grammars in comparison with other mildly context-sensitive grammar formalisms. It turns out that the complexity of this problem depends on how…

Formal Languages and Automata Theory · Computer Science 2026-03-03 Tikhon Pshenitsyn

While context-free grammars are characterized by a simple proof-theoretic grammatical formalism namely categorial grammar and its logic the Lambek calculus, no such characterizations were known for tree-adjoining grammars, and even for any…

Computation and Language · Computer Science 2021-01-12 Hiroyoshi Komatsu

In this paper, we propose a globally normalized model for context-free grammar (CFG)-based semantic parsing. Instead of predicting a probability, our model predicts a real-valued score at each step and does not suffer from the label bias…

Computation and Language · Computer Science 2021-06-08 Chenyang Huang , Wei Yang , Yanshuai Cao , Osmar Zaïane , Lili Mou

The emergence of a variety of graph-based meaning representations (MRs) has sparked an important conversation about how to adequately represent semantic structure. These MRs exhibit structural differences that reflect different theoretical…

Computation and Language · Computer Science 2020-05-01 Lucia Donatelli , Jonas Groschwitz , Alexander Koller , Matthias Lindemann , Pia Weißenhorn

In this extended abstract, we present a simple approach to convergence on term graphs that allows us to unify term graph rewriting and infinitary term rewriting. This approach is based on a partial order and a metric on term graphs. These…

Logic in Computer Science · Computer Science 2013-02-27 Patrick Bahr

Hypergraph Lambek grammars (HL-grammars) is a novel logical approach to generating graph languages based on the hypergraph Lambek calculus. In this paper, we establish a precise relation between HL-grammars and hypergraph grammars based on…

Formal Languages and Automata Theory · Computer Science 2023-11-30 Tikhon Pshenitsyn

While large models achieve impressive results, their learning dynamics are far from understood. Many domains of interest, such as natural language syntax, coding languages, arithmetic problems, are captured by context-free grammars (CFGs).…

Computation and Language · Computer Science 2026-03-02 Laura Ying Schulz , Daniel Mitropolsky , Tomaso Poggio

This paper solves an open problem concerning the generative power of nonerasing context-free rewriting systems using a simple mechanism for checking for context dependencies, in the literature known as semi-conditional grammars of degree…

Formal Languages and Automata Theory · Computer Science 2010-04-22 Tomas Masopust