Internally-disjoint directed pendant Steiner trees with three terminal vertices in Cartesian product digraphs

Shanshan Yu, Yuefang Sun

Let $D=(V(D),A(D))$ be a digraph with a terminal vertex subset $S\subseteq V(D)$ such that $|S|=k\ge 2$. An out-tree $T$ of $D$ rooted at $r$ is called a directed pendant $(S,r)$-…