Name Reiko Shinjo Waseda University Session Jan 10 15:20~15:50 E11-103 Every link has a (3,4)-diagram Given a diagram of a link, one can ignore which strand is the overstrand at each crossing and think of it as a planar $4$-valent graph embedded on the $2$-sphere. This graph divides the sphere into $n$-gons. A $(3,4)$-diagram is a diagram each of whose faces is a 3-gon or 4-gon. In this talk we show that every link has a $(3,4)$-diagram. 103-1-10/2012_1_8_8thEastAsian_final.ppt