n_y=4,
                              #geo_transform = GT(L_x = L_x, L_y = L_y),
                              show_iter=False,
                              z0_ratio=0.1,
                              MAX_ITER=100)
    n_h = cp.N_h
    n_v = cp.N_v
    n_i = cp.N_i

    face_z_t = CnstrTargetFace(F=[r_, s_, 1.7 * t_ * (r_ * (1 - r_ / L_x))]) #- s_ / 8 * (1 - s_ / L_y))])
    n_arr = np.hstack([n_h[::, (0, 2)].flatten(),
                       n_h[(0, 1, 3, 4), 1].flatten(),
     #                  n_v[:, :].flatten(),
                       n_i[1:-1, :].flatten()
                       ])
    cp.tf_lst = [(face_z_t, n_arr)]

    cp.cnstr_lhs = [[(n_h[0, 0], 1, 1.0), (n_h[1, 0], 1, -1)], # 0
                    [(n_h[0, 0], 1, 1.0), (n_h[2, 0], 1, -1)], # 1
                    [(n_h[0, 0], 1, 1.0), (n_h[3, 0], 1, -1)], # 1
                    [(n_h[0, 0], 1, 1.0), (n_h[4, 0], 1, -1)], # 1
                    [(n_h[0, -1], 1, 1.0), (n_h[1, -1], 1, -1)], # 0
                    [(n_h[0, -1], 1, 1.0), (n_h[2, -1], 1, -1)], # 1
                    [(n_h[0, -1], 1, 1.0), (n_h[3, -1], 1, -1)], # 1
                    [(n_h[0, -1], 1, 1.0), (n_h[4, -1], 1, -1)], # 1
#                    [(n_h[1, -1], 1, 1.0), (n_h[1, 0], 1, 1.0)],
                    ]

    cp.cnstr_rhs = np.zeros((len(cp.cnstr_lhs),), dtype=float)

    #del cp.eqcons['cl']