河東泰之「セミナーの準備のしかたについて」は本当に正しいのか？

河東泰之「セミナーの準備のしかたについて」は本当に正しいのか？at MATH

河東泰之「セミナーの準備のしかたについて」は本当に正しいのか？ - 暇つぶし2ch796:osed that the word problem was an important area of study in its own right,[1] together with the conjugacy problem and the group isomorphism problem. In 1912 he gave an algorithm that solves both the word and conjugacy problem for the fundamental groups of closed orientable two-dimensional manifolds of genus greater than or equal to 2.[2] Subsequent authors have greatly extended Dehn's algorithm and applied it to a wide range of group theoretic decision problems.[3][4][5] It was shown by Pyotr Novikov in 1955 that there exists a finitely presented group G such that the word problem for G is undecidable.[6] It follows immediately that the uniform word problem is also undecidable. A different proof was obtained by William Boone in 1958.[7] 略

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