THE UNIT SUM NUMBER OF POTENT RINGS

A ring R is said to be {I_{0}-}ring if each left ideal not contained in the Jacobson radical J(R) contains a non-zero idempotent. If, in addition, idempotents can be lifted modulo J(R), R is called an {I-}ring or potent rings. In this paper we prove that every element of a potent ring is a sum of two units if no factor ring of R is isomorphic to Z_2. So we answer to a conjecture of Ashish K. Srivastava [1] in affrimative. Finally we answer to an open problem of Henriksen [6] in the negative.