  The fundamental equations of Gauss, Codazzi and Ricci provide the conditions
for local isometric embeddability. In general, the three fundamental equations
are independent for surfaces in Riemannian 4-manifolds. In contrast, we prove
in this article that for arbitrary Lorentz surfaces in Lorentzian Kaehler
surfaces the equation of Ricci is a consequence of the equations of Gauss and
Codazzi.
