Conservation laws of equation family with same Kac–Moody–Virasoro symmetry

We construct conservation laws of the equation family which possesses the same infinite dimensional Kac–Moody–Virasoro symmetry algebra as the Kadomtsev–Petviashvili (KP) equation. The conservation laws are calculated up to second-order group invariants and described by two arbitrary functions of six variables and one arbitrary function with four variables.