19-01-09

The difference between r(i,j,k,t) and r(s,t) is the current sticking point. The partial of r(i,j,k,t) wrt "k" is the angle Phi. Phi is the total angle from the "k" coordinate in the global frame. Phi is the sum of the shear angle Beta and the rotation angle Theta. The partial of r(s,t) wrt "s" is the shear angle "nu" (Beta) and the partial of the directors "d" wrt "s" is the flexure "u" (Theta).