he 012, 013 and the norms and dot products of the ax12 and A43, which are already fixed. But they also have to satisfy wiAxt2 = — t2 tpak(Pt AD, taiaal3 = - t3 tpagPt /4)) (94) These two equations determine the two remaining components 012 and 013 in terms of the time differences (ti — t2) and (t