is the restriction of a (simple) representation of . See also Engel's theorem, which concerns a nilpotent Lie algebra. Lie–Kolchin theorem, which is about a (connected) solvable linear algebraic group. References Sources . Jacobson, Nathan, Lie algebras, Republication of the 1962 original. Dover Publications, Inc., New York, 1979. Jean-Pierre Serre: Complex Semisimple Lie Algebras, Springer, Berlin, 2001. Theorems about algebras