Normalizer condition for a nilpotent Lie algebra
= Normalizer condition for a nilpotent Lie algebra
Every proper <Lie subalgebra> $H$ of a finite-dimensional <Nilpotent Lie algebra> is properly contained in its <normalizer of a Lie subalgebra>[normalizer]. Choose the first term of the lower central series contained in $H$; the preceding term contains an element outside $H$ that normalizes it.