Identities with a single skew derivation

Let R be a prime ring with extended centroid C and delta, a continuous skew derivation of R. We define the notion of K-polynomials which, in the case that 5 is an ordinary derivation, reduces to polynomials of the form x(delta pn) + alpha(1)x(delta pn-1) + center dot center dot center dot + alpha(n)X(delta) wherecei alpha(i) is an element of C. It is shown that all generalized identities with 6 are consequences of GPIs of R and an identity in the form psi (x) = x(sigma m) b - bx, where Psi(x) is a K-polynomial of minimal possible order m. (c) 2005 Elsevier Inc. All rights reserved.