If the entries on the main diagonal of a upper or lower triangular matrix are all 1, the matrix is called upper or lower unitriangular. Strictly triangular matrix: If all of the entries on the main ...

Let Γ denote the algebra of all bounded infinite matrices on c, the space of convergent sequences, Δ the subalgebra of Γ consisting of lower triangular matrices. It is well known that, if H is any ...