Fréchet frames, general definition and expansions

Stevan Pilipović, Diana T. Stoeva

We define an {\it $(X_1,\Theta ,X_2)$-frame} with Banach spaces $X_2\subseteq X_1$, $|\cdot {|}_1\le |\cdot {|}_2$, and a $BK$-space $(Θ, \snorm[\cdot])$. Then by the use of decreasing sequ…