图G的线性2-荫度la2(G)是将G分解为k个边不交的森林的最小整数k,其中每个森林的分支树是长度至多为2的路.本文证明了若G是最大度为△(G)的K4-minor-free图,则la2(G)≤△(G)+5/2.
The linear 2-arboricity la2(G) of a graph G is the least integer k such that G can be partitioned in to k edge-disjoint forests,whose component trees are paths of length at most2.We prove that la2(G)≤△(G)+5/2 if G is a K4-minor-free graph with maximum degree △(G).