A Short Proof of the Hass–lagarias Theorem
نویسنده
چکیده
We give a short proof of the Hass–Lagarias theorem on an upper bound on the minimal number of elementary moves to unknot in a triangulated 3-manifold. Our method uses a normal form for surfaces whose boundary is contained in the 1-skeleton of a triangulated 3-manifold. We also obtain a significantly better upper bound of 2, where t is the number of tetrahedra, and improve the Hass–Lagarias upper bound on the number of Reidemeister moves needed to unknot to 2 4 , where n is the crossing number.
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