ON THE (B, N)-CONSTRUCTION

In this paper, k will denote an arbitrary field. If m, n are natural numbers, then $M_{m \times n}(k)$ will denote the set of all $m \times n$ matrices with entries in k. Every k-algebras will be assumed to contain a (multiplicative) identity $1 \neq 0$. A k-subspace $R_0$ of a k-algebra R will be called a k-subalgebra of R if $R_0$ is closed under multiplication from R and $R_0$ contains the identity of R. We will assume all k-algebra homomorphisms take the identity to identity.