  A contour plot of positive iso-J curves is shown for a gravitational binary
lens epsilon_2 = 0.1883 and ell = 0.687. The caustic curve is made of 4-cusped
central caustic (so-called "stealth bomber") on the lens axis and two
triangular caustics off the lens axis. The cusps of the trioids are all
negative cusps. The positive image magnification contours outside the positive
cusps on the lens axis are elongated along the symmetry axis. It is in contrast
with figure 4 of astro-ph/0206162 (Gaudi and Petters) where the contours appear
to contract along the symmetry axis. We apologize if our citation of their
figure 4 without the caution played any role of causing confusion with readers.
