An experimental study of algorithms for obtaining a singly connected subgraph

A directed graph G = (V,E) is singly connected if for any two vertices v, u of V, the directed graph G contains at most one simple path from v to u. In this paper, we study different algorithms to find a feasible but necessarily optimal solution to the following problem. Given a directed acyclic graph G = (V, E), find a subset H of E of minimum size such that the subgraph (V, E-H) is singly connected. Moreover, we prove that this problem can be solved in polynomial time for a special kind of directed graphs