Central ideal

Symbol-free definition
A subset of a Lie ring is termed a central ideal if it satisfies the following equivalent conditions:


 * 1) It is a subgroup of the additive group and is contained in the center of the Lie ring.
 * 2) It is a subring and is contained in the center of the Lie ring.
 * 3) It is an ideal and is contained in the center of the Lie ring.

Weaker properties

 * Stronger than::Abelian ideal
 * Stronger than::Ideal of a Lie ring