Direct factor is not intersection-closed
This article gives the statement, and possibly proof, of a subgroup property not satisfying a subgroup metaproperty .
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Statement
The intersection of two direct factors of a group need not be a direct factor. In fact, this property is not even true within -groups.
Proof
The counterexample
Let denote the cyclic group on elements. Then, consider the group . Consider the automorphism of this group which sends the pair to . Consider the intersection of the group (which is a direct factor) with its image under . This is basically the subgroup of comprising elements which are multiples of . Clearly, this is not a direct factor, in fact it is not even a direct factor inside .