In: Tatra Mountains Mathematical Publications, vol. 46, no. 2
Aleksandra Karasińska - Elżbieta Wagner-Bojakowska
Detaily:
Rok, strany: 2010, 85 - 89
Kľúčové slová:
density of a set at a point, $\rho$-upper continuous functions, approximately continuous functions,
Baire 1 functions, Denjoy property.
O článku:
The notion of a $\rho$-upper continuous function is a generalization of the notion
of an approximately continuous function.
It was introduced by S. Kowalczyk and K. Nowakowska.
In
[Kowalczyk, S., Nowakowska, K.:
\textit{A note on~$\rho $-upper continuous functions},
Tatra. Mt. Math. Publ. \textbf{44} (2009), 153--158].
the authors proved that each $\rho$-upper continuous function is measurable
and has Denjoy property.
In this note we prove that there exists a measurable function having Denjoy property
which is not $\rho$-upper continuous function for any $\rho\in[0,1)$
and there exists a function which is $\rho$-upper continuous for each $\rho \in [0,1)$
and is not approximately continuous.
In the paper [Kowalczyk, S.---Nowakowska, K.:
\textit{A~note on $\rho $-upper continuous functions},
Tatra. Mt. Math. Publ. \textbf{44} (2009), \hbox{153--158}] there is
also proved that for each $\rho\in(0,\frac{1}{2})$
there exists a $\rho$-upper continuous function which is not in the first class of Baire.
Here we show that there exists a function which is $\rho$-upper continuous for each $\rho\in[0,1)$
but is not Baire 1 function
Ako citovať:
ISO 690:
Karasińska, A., Wagner-Bojakowska, E. 2010. Some remarks on $ρ$-upper continuous functions. In Tatra Mountains Mathematical Publications, vol. 46, no.2, pp. 85-89. 1210-3195.
APA:
Karasińska, A., Wagner-Bojakowska, E. (2010). Some remarks on $ρ$-upper continuous functions. Tatra Mountains Mathematical Publications, 46(2), 85-89. 1210-3195.