Resolutions of unbounded complexes
Rewriting on cyclic structures : equivalence between the operational and the categorical description
Rewriting on cyclic structures: Equivalence between the operational and the categorical description
We present a categorical formulation of the rewriting of possibly cyclic term graphs, based on a variation of algebraic 2-theories. We show that this presentation is equivalent to the well-accepted operational definition proposed by Barendregt et al. – but for the case of circular redexes , for which we propose (and justify formally) a different treatment. The categorical framework allows us to model in a concise way also automatic garbage collection and rules for sharing/unsharing and...
Ring epimorphisms and .
Risoluzione di moduli su domini d'integrità noetheriani con proprietà di estensione
Roots of Nakayama and Auslander-Reiten translations
We discuss the roots of the Nakayama and Auslander-Reiten translations in the derived category of coherent sheaves over a weighted projective line. As an application we derive some new results on the structure of selfinjective algebras of canonical type.
Roots of unity as a Lie algebra.
-categories
Salvetti complex, spectral sequences and cohomology of Artin groups
The aim of this short survey is to give a quick introduction to the Salvetti complex as a tool for the study of the cohomology of Artin groups. In particular we show how a spectral sequence induced by a filtration on the complex provides a very natural and useful method to study recursively the cohomology of Artin groups, simplifying many computations. In the last section some examples of applications are presented.
Same Applications of Beilinson's Theorem to Projective Spaces and Quadrics.
Samuel compactification and uniform coreflection of nearness -frames
We introduce the structure of a nearness on a -frame and construct the coreflection of the category of nearness -frames to the category of compact regular -frames. This description of the Samuel compactification of a nearness -frame is in analogy to the construction by Baboolal and Ori for nearness frames in [1] and that of Walters for uniform -frames in [11]. We also construct the uniform coreflection of a nearness -frame, that is, the coreflection of the category of to the category...
Saunders Mac Lane, the knight of mathematics.
Searching for more absolute CR-epic spaces.
Self--injective abelian groups
Self-equivalences of the derived category of Brauer tree algebras with exceptional vertex.
Selfinjective algebras of wild canonical type
We develop the representation theory of selfinjective algebras which admit Galois coverings by the repetitive algebras of algebras whose derived category of bounded complexes of finite-dimensional modules is equivalent to the derived category of coherent sheaves on a weighted projective line with virtual genus greater than one.
Semantics of value recursion for monadic input/output
Monads have been employed in programming languages for modeling various language features, most importantly those that involve side effects. In particular, Haskell’s IO monad provides access to I/O operations and mutable variables, without compromising referential transparency. Cyclic definitions that involve monadic computations give rise to the concept of value-recursion, where the fixed-point computation takes place only over the values, without repeating or losing effects. In this paper, we...
Semantics of value recursion for Monadic Input/Output
Monads have been employed in programming languages for modeling various language features, most importantly those that involve side effects. In particular, Haskell's IO monad provides access to I/O operations and mutable variables, without compromising referential transparency. Cyclic definitions that involve monadic computations give rise to the concept of value-recursion, where the fixed-point computation takes place only over the values, without repeating or losing effects. In this paper,...
Sémantique catégorique des constructeurs de types d'ordre supérieur
Sémantique catégorique des types : comprendre le système F