“…In the case that G has a cycle, the global stability property is not valid any more as studied in Johansson (2009, 2010). While G has been assumed to be a tree for the investigation of global stability properties of E ′ p * in Johansson (2008, 2010), it can be shown that if (G, p * ) is rigid, E p * is locally asymptotically stable with respect to (32) under the gradient control law based on (34) by using the result in Oh and Ahn (2014a). Oh and Ahn (2011b,c,e) have proposed a distance-based formation control law for the agents (25), which is aimed to allow inter-agent distances to converge to desired values in some desired manner.…”