Remarks on the rings of functions which have a finite numb er of di scontinuities

[EN] Let X be an arbitrary topological space. F(X) denotes the set of all real-valued functions on X and C(X)F denotes the set of all f ∈ F(X) such that f is discontinuous at most on a finite set. It is proved that if r is a positive real number, then for any f ∈ C(X)F which is not a unit of C(X)F t...

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Detalhes bibliográficos
Autores: Ahmadi Zand, Mohammad Reza, Khosravi, Zahra
Tipo de documento: artigo
Data de publicação:2021
País:España
Recursos:Universitat Politècnica de València (UPV)
Repositório:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Idioma:inglês
OAI Identifier:oai:riunet.upv.es:10251/165247
Acesso em linha:https://riunet.upv.es/handle/10251/165247
Access Level:Acceso aberto
Palavra-chave:C(X)F
Z-ultrafilter
Completely separated
C(X)F -embedded
Z-filter
Over-rings of C(X)
Artinian ring
Descrição
Resumo:[EN] Let X be an arbitrary topological space. F(X) denotes the set of all real-valued functions on X and C(X)F denotes the set of all f ∈ F(X) such that f is discontinuous at most on a finite set. It is proved that if r is a positive real number, then for any f ∈ C(X)F which is not a unit of C(X)F there exists g ∈ C(X)F such that g ≠ 1 and f = gr f. We show that every member of C(X)F is continuous on a dense open subset of X if and only if every non-isolated point of X is nowhere dense. It is shown that C(X)F is an Artinian ring if and only if the space X is finite. We also provide examples to illustrate the results presented herein.