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Related papers: Words and morphisms with Sturmian erasures

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We propose an unsupervised neural model for learning a discrete embedding of words. Unlike existing discrete embeddings, our binary embedding supports vector arithmetic operations similar to continuous embeddings. Our embedding represents…

Computation and Language · Computer Science 2020-10-16 Masataro Asai , Zilu Tang

A word is called a reset word for a deterministic finite automaton if it maps all the states of the automaton to a unique state. Deciding about the existence of a reset word of a given maximum length for a given automaton is known to be an…

Formal Languages and Automata Theory · Computer Science 2014-09-09 Vojtěch Vorel

Let A be an alphabet and W be a set of words in the free monoid A*. Let S(W) denote the Rees quotient over the ideal of A* consisting of all words that are not subwords of words in W. We call a set of words W finitely based if the monoid…

Group Theory · Mathematics 2016-09-09 Olga Sapir

We present a game semantics for Linear Logic, in which formulas denote games and proofs denote winning strategies. We show that our semantics yields a categorical model of Linear Logic and prove full completeness for Multiplicative Linear…

Logic in Computer Science · Computer Science 2013-11-26 Samson Abramsky , Radha Jagadeesan

We study the notion of quasiperiodicity, in the sense of "coverability", for biinfinite words. All previous work about quasiperiodicity focused on right infinite words, but the passage to the biinfinite case could help to prove stronger…

Discrete Mathematics · Computer Science 2018-03-08 Florian Barbero , Guilhem Gamard , Anaël Grandjean

We introduce a guessing game, permutation Wordle, in which a guesser attempts to recover a hidden permutation in $S_n$. In each round, the guesser guesses a permutation (using information from previous rounds) and is told which entries of…

Combinatorics · Mathematics 2026-01-27 Samuel A. Kutin , Lawren M. Smithline

We introduce string diagrams as a formal mathematical, graphical language to represent, compose, program and reason about games. The language is well established in quantum physics, quantum computing and quantum linguistic with the…

Computer Science and Game Theory · Computer Science 2016-04-21 Jules Hedges , Evguenia Shprits , Viktor Winschel , Philipp Zahn

Motivated by a conjecture of Frid, Puzynina, and Zamboni, we investigate infinite words with the property that for infinitely many n, every length-n factor is a product of two palindromes. We show that every Sturmian word has this property,…

Combinatorics · Mathematics 2015-09-18 Adam Borchert , Narad Rampersad

Smooth words over an alphabet of non-negative integers $\{a,b\}$ are infinite words that are infinitely derivable, the most famous example being the Oldenburger-Kolakoski word over $\{1,2\}$. The main way to study their language is to…

Formal Languages and Automata Theory · Computer Science 2026-05-01 Julien Cassaigne , Raphaël Henry

The concept of a morphism determined by an object provides a method to construct or classify morphisms in a fixed category. We show that this works particularly well for triangulated categories having Serre duality. Another application of…

Category Theory · Mathematics 2011-10-26 Henning Krause

We prove an inequality for the number of periods in a word x in terms of the length of x and its initial critical exponent. Next, we characterize all periods of the length-n prefix of a characteristic Sturmian word in terms of the lazy…

Discrete Mathematics · Computer Science 2020-05-28 Daniel Gabric , Narad Rampersad , Jeffrey Shallit

We prove that outer commutator words are uniformly concise, i.e. if an outer commutator word w takes m different values in a group G, then the order of the verbal subgroup w(G) is bounded by a function depending only on m and not on w or G.…

Group Theory · Mathematics 2014-02-26 Gustavo A. Fernández-Alcober , Marta Morigi

A word is \emph{square-free} if it does not contain non-empty factors of the form $XX$. In 1906 Thue proved that there exist arbitrarily long square-free words over $3$-letter alphabet. We consider a new type of square-free words. A…

Combinatorics · Mathematics 2019-10-15 Jarosław Grytczuk , Hubert Kordulewski , Artur Niewiadomski

We show that the coding of rotation by $\alpha$ on $m$ intervals with rationally independent lengths can be recoded over $m$ Sturmian words of angle $\alpha.$ More precisely, for a given $m$ an universal automaton is constructed such that…

Combinatorics · Mathematics 2007-05-23 Jean Berstel , Laurent Vuillon

We consider the (one-dimensional) array counterpart of contextual as well as insertion and deletion string grammars and consider the operations of array insertion and deletion in array grammars. First we show that the emptiness problem for…

Formal Languages and Automata Theory · Computer Science 2013-09-06 Rudolf Freund , Sergiu Ivanov , Marion Oswald , K. G. Subramanian

A monoid is called special if it admits a presentation in which all defining relations are of the form $w = 1$. Every group is special, but not every monoid is special. In this article, we describe the language-theoretic properties of the…

Group Theory · Mathematics 2021-11-23 Carl-Fredrik Nyberg-Brodda

This note contains some results related to the definitions of toroidal embeddings and toroidal morphisms over non-closed fields of characteristic zero.

Algebraic Geometry · Mathematics 2013-03-21 Jan Denef

An abelian square is the concatenation of two words that are anagrams of one another. A word of length $n$ can contain at most $\Theta(n^2)$ distinct factors, and there exist words of length $n$ containing $\Theta(n^2)$ distinct…

Discrete Mathematics · Computer Science 2017-02-27 Gabriele Fici , Filippo Mignosi , Jeffrey Shallit

The avoidability, or unavoidability of patterns in words over finite alphabets has been studied extensively. A word (pattern) over a finite set is said to be unavoidable if, for all but finitely many words, there exists a morphism mapping…

Formal Languages and Automata Theory · Computer Science 2019-07-16 Paul Sauer

Using Reiner's definition of Stirling numbers of type B of the second kind, we provide a 'balls into urns' approach for proving a generalization of a well-known identity concerning the classical Stirling numbers of the second kind:…

Combinatorics · Mathematics 2019-03-08 Eli Bagno , David Garber