“…A vertex representing T, Q, P e and H is connected with 3, 4, 5 and 6 edges, respectively. A TG is similar to a CG, except that each of edges is composed of some B connected in series [12,31]. Let F be DoF of the mechanism, n k (k = 3, …, 6) be the numbers of (T, Q, P e , H) in TGs and CGs, respectively.…”