Results 71 to 80 of about 20,804 (234)
The categorical contours of the Chomsky-Sch\"utzenberger representation theorem [PDF]
Logical Methods in Computer ScienceWe develop fibrational perspectives on context-free grammars and on nondeterministic finite-state automata over categories and operads. A generalized CFG is a functor from a free colored operad (aka multicategory) generated by a pointed finite species ...
Paul-André Melliès, Noam Zeilberger
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Infix Congruences on a Free Monoid [PDF]
Transactions of the American Mathematical Society, 1989 A subset T of the free monoid \(X^*\) on a finite alphabet X is said to be an infix code if u,xuy\(\in T\) \(\Rightarrow\) \(xy=1\). An infix congruence is a congruence on \(X^*\) whose classes are infix codes; if these classes are also finite, the congruence is said to be f- disjunctive.
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The flat cover conjecture for monoid acts
Journal of the London Mathematical Society, Volume 112, Issue 6, December 2025.Abstract We prove that the Flat Cover Conjecture holds for the category of (right) acts over any right‐reversible monoid S$S$, provided that the flat S$S$‐acts are closed under stable Rees extensions. The argument shows that the class F$\mathcal {F}$‐Mono (S$S$‐act monomorphisms with flat Rees quotient) is cofibrantly generated in such categories ...
Sean Cox
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Linear Algebra and its Applications, 1976 AbstractA matrix characterization is obtained for the epimorphisms in the category of finitely generated free monoids. It follows from our result that it is effectively decidable whether a given morphism is an epimorphism. The corresponding question for monomorphisms has been answered in the algorithm of Sardinas and Patterson.
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Is every product system concrete?
Transactions of the London Mathematical Society, Volume 12, Issue 1, December 2025.Abstract Is every product system of Hilbert spaces over a semigroup P$P$ concrete, that is, isomorphic to the product system of an E0$E_0$‐semigroup over P$P$? The answer is no if P$P$ is discrete, cancellative and does not embed in a group. However, we show that the answer is yes for a reasonable class of semigroups.
S. Sundar
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New and old results on spherical varieties via moduli theory
, 2018 Given a connected reductive algebraic group $G$ and a finitely generated monoid $\Gamma$ of dominant weights of $G$, in 2005 Alexeev and Brion constructed a moduli scheme $\mathrm M_\Gamma$ for multiplicity-free affine $G$-varieties with weight monoid ...
Avdeev, Roman, Cupit-Foutou, Stéphanie
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Real models for the framed little n$n$‐disks operads
Journal of Topology, Volume 18, Issue 4, December 2025.Abstract We study the action of the orthogonal group on the little n$n$‐disks operads. As an application we provide small models (over the reals) for the framed little n$n$‐disks operads. It follows in particular that the framed little n$n$‐disks operads are formal (over the reals) for n$n$ even and coformal for all n$n$.
Anton Khoroshkin, Thomas Willwacher
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Uniform generation in trace monoids
, 2015 We consider the problem of random uniform generation of traces (the elements of a free partially commutative monoid) in light of the uniform measure on the boundary at infinity of the associated monoid.
BP Kitchens +13 more
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Actions of a separately strict cpo-monoid on pointed directed complete posets [PDF]
Categories and General Algebraic Structures with Applications, 2015 In the present article, we study some categorical properties of the category {$bf Cpo_{Sep}$-$S$} of all {separately strict $S$-cpo's}; cpo's equipped with a compatible right action of a separately strict cpo-monoid $S$ which is strict continuous ...
Halimeh Moghbeli Damaneh
doaj
Unambiguous erasing morphisms in free monoids [PDF]
RAIRO - Theoretical Informatics and Applications, 2009 Summary: This paper discusses the fundamental combinatorial question of whether or not, for a given string \(\alpha \), there exists a morphism \(\sigma \) such that \(\sigma \) is unambiguous with respect to \(\alpha \), i.e. there exists no other morphism \(\tau \) satisfying \(\tau (\alpha ) = \sigma (\alpha )\). While \textit{D. D. Freydenberger, D.
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