On the $c_0$-equivalence and permutations of series

Artur Bartoszewicz, Włodzimierz Fechner, Aleksandra Świątczak +1

Assume that a convergent series of real numbers $\sum _{n=1}^{\infty }{a}_n$ has the property that there exists a set $A\subseteq \mathbb{N}$ such that the series $\sum\limits_{n \in A}…