Abstract

Let R be a prime ring, char R\neq 2,3 \, \sigma, \tau : R\rightarrow R two automorphisms, U a nonzero (\sigma, \tau)- Lie ideal of R and o\neq d : R\rightarrow R$ a derivation such that \sigma d = d\sigma, \tau d = d\tau. In this paper we have proved the following results. (1) If d (U) \subset Z then U\subset Z (2) If d(U) \subset U and d^2 (U) \subset Z then U\subset Z.