Simpler and efficient characterizations of tree t-spanners for graphs with few P4's and (k, l)-graphs

Fernanda Couto, Luís Cunha, Diego Ferraz

A tree $t$-spanner of a graph $G$ is a spanning tree $T$ in which the distance between any two adjacent vertices of $G$ is at most $t$. The smallest $t$ for which $G$ has a tree $t…