arXiv · 1103.2784
We show that every group with free $\mathbb{Z}^n$-length function is CAT(0).
Inna Bumagin, Olga Kharlampovich. 2013-05-21. $Z^n$-free groups are CAT(0). https://doi.org/10.1112/jlms%2Fjdt037
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