2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/150222It is shown that if the ring of constants of a restricted differential Lie algebra with a quasi-Frobenius inner part satisfies a polynomial identity (PI) then the original prime ring has a generalized polynomial identitiy (GPI). If additionally the ring of constants is semiprime then the original ring is PI. The case of a non-quasi-Frobenius inner part is also considered.20 pages, LaTex2e, to appear in Israel Journal of Mathematics, volume 96, part B, 1996 (357-377)Algebraic GeometryQuantum Algebratext