This is a question about Hirshon's paper "The center and the commutator subgroup in hopfian groups". In Theorem 12, he showed that if $B$ is a perfect group and $A$ is a hopfian group, then the direct product $A \times B$ is hopfian. Does $B$ have to be a group with finitely many normal subgroups?
Direct product of hopfian groups
Shijie Gu
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