Equivalence of definitions of image-closed characteristic subgroup of finite abelian group
Statement
Suppose in a finite abelian group and is a subgroup of . The following are equivalent:
- is an Image-closed characteristic subgroup (?) of : for any surjective homomorphism from , the image of is characteristic in the image of .
- is an Image-closed fully invariant subgroup (?) of : for any surjective homomorphism from , the image of is fully invariant in the image of .
- is a Verbal subgroup (?) of .
- For every prime , the -Sylow subgroup of is an agemo subgroup of the -Sylow subgroup of .