학과 세미나 및 콜로퀴엄
박종호 (KAUST)계산수학 세미나
Advanced Iterative Methods as Elementary Iterations on Larger Spaces — Part I: Motivations and Preliminaries
박종호 (KAUST)계산수학 세미나
Advanced Iterative Methods as Elementary Iterations on Larger Spaces — Part II: Theory
박종호 (KAUST)계산수학 세미나
Advanced Iterative Methods as Elementary Iterations on Larger Spaces — Part III: Applications
이동규 (KAIST)기타
Introduction to Étale Cohomology and the Weil Conjectures 2/4
Peter Yi Wei (University of Arkansas)대수기하학
A Generalization of Green’s Theorem to Symmetric Products of Curves
대학원생 세미나
편미분방정식 통합연구실 세미나
IBS-KAIST 세미나
AI수학대학원 세미나
MFRS 세미나
역문제 기초연구실 세미나
학술회의 및 워크샵
학생 뉴스
북마크
Research Highlights
게시판
동문 뉴스
Problem of the week
Trefoil to Figure-Eight by Crossing Changes
A knot is a simple closed curve in three-dimensional space. A diagram of a knot is a projection of the knot to the plane together with over/under information at each crossing. A crossing change is the operation of switching one crossing from over to under or from under to over.
Find up to three examples of sequences of knot diagrams that begin with a diagram of the trefoil knot and end with a diagram of the figure-eight knot, where each step is obtained from the previous diagram by a crossing change.
The obvious chains trefoil → unknot → figure-eight and trefoil → trefoil # figure-eight → figure-eight are not allowed.
(3 points will be given for three correct examples, 2 points for two correct examples, and 1 point for one correct example.)
