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arXiv · 2006.15523

The Klein bottle group is not strongly verbally closed, though awfully close to being so

Anton A. Klyachko
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Abstract

According to Mazhuga's theorem, the fundamental group $H$ of any connected surface, possibly except for the Klein bottle, is a retract of each finitely generated group containing $H$ as a verbally closed subgroup. We prove that the Klein bottle group is indeed an exception but has a very close property.

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Anton A. Klyachko. 2020-06-28. The Klein bottle group is not strongly verbally closed, though awfully close to being so. https://doi.org/10.4153/s0008439520000582

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