Let A, B, C and D denote four reference frames, composed of mutuality orthogonal unit vectors ai, bi, ci and di (i=1,2,3), respectively. Assume that rotation matrices aRc, aRd and bRd are given. Let x, y, z and t denote some specified constants. Given vector a[g] = [ x y z]T expressed in reference frame A and c[h] = [ y t x ]T expressed in reference frame C, add these vectors and express the result in coordinate frame B.