In the product space H^n × R; we obtain uniform a priori C^0 horizontal length estimates, uniform a priori C^1 boundary gradient estimates, as well as uniform modulus of continuity, for a class of horizontal minimal equations. In two independent variables, we derive a certain uniform global a priori C^1 estimates and we infer an existence result
UNIFORM A PRIORI ESTIMATES FOR A CLASS OF HORIZONTAL MINIMAL EQUATIONS.