“…Triangle on graph represents a subchain or a 2R joints. If RPS is constructed with subchains numbered (34,10,9), (33,19,18), (31,16,30), (28,14,37), (26,25,36), and (23,22,35), only one subchain is enough to prevent the movement. If RPS is constructed with six extra R joints, the plates numbered 28, 31, 19, 10, 23, and 26 have two 2R joints, respectively, (aj, af), (am, al), (t, v), (z, t) (aa, ab) (ae, ac) instead of three R joints.…”