We prove that the tree-width of graphs in a hereditary class defined by a finite set $F$ of forbidden induced subgraphs is bounded if and only if $F$ includes a complete graph, a complete bipartite graph, a tripod (a forest in which every connected component has at most 3 leaves) and the line graph of a tripod.

翻译：我们证明,如果而且只有在美元包括完整的图表、完整的双方图表、三脚架(每个相关组成部分最多有三个叶子的森林)和三脚架的直线图的情况下,才能对受禁诱导子座下一定限额的F美元定义的世袭类别中的图树宽加以约束。