On the Characterization of a Class of Four Dimensional Matrices and Steinhaus Type Theorems

M. Yeşi̇lkayagi̇l, F. Başar

In the present paper, we give the definitions of four dimensional conull and coregular matrices, and characterize the classes $(\mathcal{M}_{u}:\mathcal{C}_{\vartheta})$, where $\vartheta\in \{p,p0,f\}$ and $\mathcal{C}_{f}$ denotes the space of all almost convergent double sequences. Additionally, we give two Steinhaus type theorems related to the coercive/almost coercive four dimensional sequence to sequence matrix transformations.