In 1981, Tuza conjectured that the cardinality of a minimum set of edges that intersects every triangle of a graph is at most twice the cardinality of a maximum set of edge-disjoint triangles. This conjecture have been proved for several important graph classes, as planar graphs, tripartite graphs, among others. However, it remains open on other important classes of graphs, as chordal graphs. Furthermore, it remains open for main subclasses of chordal graphs, as split graphs and interval graphs. In this paper, we show that Tuza's conjecture is valid for co-chain graphs with even number of vertices in both sides of the partition, a known subclass of interval graphs.

翻译：1981年，Tuza猜想：图中所有三角形的最小边交集的基数，不超过最大边不交三角形集合基数的两倍。该猜想已在平面图、三部图等重要图类中得到证明，但在弦图等其他重要图类中仍悬而未决。此外，针对弦图的主要子类（如分裂图和区间图）也尚未解决。本文证明，当分割两侧顶点数均为偶数时，Tuza猜想对已知的区间图子类——共链图成立。