Low regularity for the fifth order Kadomtsev-Petviashvili-I type equation

It follows that the fifth order Kadomtsev-Petviashvili-I equation (0.1) is locally well-posed in Hs,0 with s≥−3/4, where the norm Hs,r is defined by‖f‖H(x,y)s,r=‖〈ξ〉s〈ζ〉rfˆ‖L(ξ,ζ)2.