ソファ問題 - Wikipedia
Kallus, Yoav; Romik, Dan (December 2018). “Improved upper bounds in the moving sofa problem”. Advances in Mathematics 340: 960–982. arXiv : 1706.06630 . doi : 10.1016/j.aim.2018.10.022 . Romik, Dan (2017). “Differential equations and exact solutions in the moving sofa problem”. Experimental Mathema...
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