“…where f β is the bearing density function. From ( 21) and (15) it is possible to calculate the probability that vessel j needs to give way, i.e. as the sum of probabilities of all the elements of G ⊂ S 2 G = {(HO, HO), (HO, OT ), (HO, P S), (SB, HO), (SB, SB), (SB, OT ), (SB, OT ), (OT, OT ), (P S, OT ), (P S, P S)}, (27) where G contains all the elements of S 2 where the second element q in the tuple (p, q) is q = 1.…”