curvature into the three-dimensional Euclidean space is considered through the Gauss--
Codazzi equations for the first and second fundamental forms. The large L^∞ solution is
obtained, which leads to a C^1,1 isometric immersion. The approximate solutions are
constructed by the Lax--Friedrichs finite-difference scheme with the fractional step. The
uniform estimate is established by studying the equations satisfied by the Riemann …