Normal coalition class

Origin of the term
The term normal coalition class was introduced by J.E. Roseblade in the paper On Certain Subnormal Coalition Classes in Journal of Algebra, I, 132-138 (1964).

Definition with symbols
A group property $$p$$ of groups is said to give a normal coalition class if whenever $$G$$ is a group and $$H_1$$ and $$H_2$$ are normal subgroups of $$G$$ both satisfying $$p$$ as groups, then the subgroup $$H_1H_2$$ also satisfies $$p$$.

Examples

 * The group property of being finite