Subgroup contained in finitely many intermediate subgroups
From Groupprops
This article defines a subgroup property: a property that can be evaluated to true/false given a group and a subgroup thereof, invariant under subgroup equivalence. View a complete list of subgroup properties[SHOW MORE]
Contents
Definition
Symbol-free definition
A subgroup of a group is said to be contained in finitely many intermediate subgroups if the number of subgroups of the whole group containing that subgroup is finite.
Definition with symbols
A subgroup of a group
is said to be contained in finitely many intermediate subgroups if the number of subgroups
of
such that
is finite.
Relation with other properties
Stronger properties
Facts
- If a normal subgroup is contained in only finitely many intermediate subgroups, it has finite index. This follows from the fourth isomorphism theorem and the fact that a group having finitely many subgroups is finite.