This item compares the boundary surface and stable manifold of a ternary memory. It points out to their consistency in the case of conventional saddle singularity. The other case, however, occurs at the second saddle -so called virtual. Then the boundary surface calculated using grid method differs from the stable manifold calculated by backward integration technique. The suggested procedure of calculating the stable manifold is hard for calculating and depicting a large number of trajectories -carriers of information about the stable manifold. After calculating the trajectories, stable manifold itself is depicted using the contour lines in the projection into u1, u2 plane.