“…Theorem 2. In R 2 , suppose that 0 ≤ α i (0) ≤ π 2 for i = 1, … , n. Under Assumptions 1 and 2 and the control law (9), α → 0 asymptotically, ie, the agents asymptotically converge to a formation satisfying all the desired bearing vectors. α i = α j ∀i, j = 1, … , n and one of the following conditions holds: (i) α i = α j = 0, ∀i, j = 1, … , n or (ii) there exists a straight line in 2D such that all desired bearing vectors g * i are equally inclined with it by an angle α.…”