Vertex linear arboricity

Vertex linear arboricity --- вершинно линейная древесность.

The vertex linear arboricity [math]\displaystyle{ vla(G) }[/math] of a graph [math]\displaystyle{ G }[/math] is the minimum number of subsets into which the vertex set [math]\displaystyle{ V(G) }[/math] can be partitioned so that each subset induces a subgraph whose connected components are paths.