Generalized Lie-B\"acklund theorem for Lie class \omega=1 overdetermined   systems
  In this paper we prove a version of Lie-B\"acklund theorem for overdetermined systems of scalar PDEs, whose general solution depends on 1 function of 1 variable. This generalizes the case of involutive system of the second order on the plane treated by E.Cartan in 1910. Many examples are provided. 
Boris Kruglikov
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