Article History
Received: 21 May 2024
Accepted: 6 December 2024
First Online: 24 December 2024
Acknowledgements
: This research is carried out within the national group GNAMPA of INDAM. The first and the third authors are partially supported by the Department of Mathematics and Computer Science of the University of Perugia (Italy) and by the projects “Fondi di funzionamento per la ricerca dipartimentale -Anno 2021", “Metodi della Teoria dell’Approssimazione, Analisi Reale, Analisi Nonlineare e loro applicazioni" and “Integrazione, Approssimazione, Analisi Nonlineare e loro Applicazioni", funded by the 2018 and 2019 basic research fund of the University of Perugia.