Characteristic Semi-simple Lie Algebras and Completely Semi-simple Lie Algebras over any Field

In this paper, we study some properties of the finite dimensional characteristic semi-simple (C.S.S.) Lie algebras and completely semi-simple Lie algebras over any field. The definitions and some results of these algebras have been given by G.B.Seligman in 1]. We can easily prove the following lemmas: Lemma 1 The centre of any finite dimensional Lie algebra L is a characteristic ideal of L.