# Order-conjugate not implies order-dominating

This article gives the statement and possibly, proof, of a non-implication relation between two subgroup properties. That is, it states that every subgroup satisfying the first subgroup property (i.e., order-conjugate subgroup) need not satisfy the second subgroup property (i.e., order-dominating subgroup)
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## Definition

We can have a group $G$ with an order-conjugate subgroup $H$ (i.e., a subgroup $H$ that is conjugate to any other subgroup of the same order) that is not an order-dominating subgroup: in other words, there exists a subgroup $K$ of $G$ whose order divides the order of $H$, but such that $K$ is not contained in any conjugate of $H$.

## Proof

### Example of the alternating group of degree five

Further information: alternating group:A5

Suppose $G$ is the alternating group on the set $S = \{ 1,2,3,4,5 \}$. Suppose $H$ is the subgroup of $G$ that is the alternating group on $\{ 1,2,3,4 \}$. In other words, $H$ is the stabilizer of the point $\{ 5 \}$. Then, $H$ is order-conjugate in $G$: the subgroups of the same order as $H$ are precisely the stabilizers of points in $S$, and these are conjugate to $H$ by suitable $5$-cycles.

On the other hand, consider the subgroup $K$: $K := \{ (), (1,2,3), (1,3,2), (1,2)(4,5), (2,3)(4,5), (1,3)(4,5) \}$. $K$ is a group of order six, isomorphic to the symmetric group of degree three. However, $K$ is not contained in any conjugate of $H$, because any conjugate of $H$ stabilizes some element, and $K$ does not stabilize any element.