“…The linear equations corresponding to Eqs. (12)(13)(14)(15) for the homogeneous and symmetric system are given by: where ∆x n = x n,1 − x n,2 , ∆y n = y n,1 − y n,2 , δx n = x n,i − x n−1,i and δy n = y n,i − y n−1,i . In the symmetric equilibrium state it holds that L x n,2 = −L x n,1 =…”