幂等

This paper is a study on the invertibility of the commutator of scalar-idempotent elements and scalar-involutory elements of a unitary ring.

本文研究在一个有单位元环中两个倍元换位子与两个倍对合元换位子性问题。

The necessary and sufficient conditions of similarity of two idempotent matrices are proved, the idempotency of linear combinations of two idempotent matrices is discussed.

摘要证明数域上两个同阶相似充要条件是它们有相同秩；给出相似标准型；讨论两个线性组合仍是充要条件。