Derivable Maps of Prime Rings
Prime ring
Idempotent element
Derivable map
Additive map.
Our active aim in this paper is to prove the following Let Ŕ be a ring having an
idempotent element e(e 0,e 1) . Suppose that R is a subring of Ŕ which
satisfies:
(i) eR R and Re R .
(ii) xR 0 implies x 0 .
(iii ) eRx 0 implies x 0( and hence Rx 0 implies x 0) .
(iv) exeR(1 e) 0 implies exe 0 .
If D is a derivable map of R satisfying D(R ) R ;i, j 1,2. ij ij Then D is
additive. This extend Daif's result to the case R need not contain any non-zero
idempotent element.
