(n,d)-环的若干性质

On some properties of(n,d)-rings

若R,S皆为左(n,d)-环,则R S亦为左(n,d)-环;设R与S是Morita等价的,则R为左(n,d)-环当且仅当S为左(n,d)-环.

If R and Sare（n,d）-rings, then so is R@S; If R and Sare Morita equivalent and R is a（n,d）-ring, then so is S.