La borne de Jacobi pour une diffi{é}t{é} d{é}finie par un syst{è}me quasi r{é}gulier

英文摘要：

We show that Jacobi's bound for the order of a system of ordinary differential equations stands in the case of a diffiety defined by a quasi-regular system. We extend the result when there are less equations than variables and characterize the case when the bound is reached.