∀ {G : Type u_1} [inst : MeasurableSpace G] [inst_1 : AddGroup G] [MeasurableAdd₂ G] (μ ν : MeasureTheory.Measure G)
  [MeasureTheory.SFinite ν] [MeasureTheory.SFinite μ] [MeasurableNeg G] [μ.IsAddLeftInvariant] [ν.IsAddLeftInvariant],
  MeasureTheory.MeasurePreserving (fun z => (z.2 + z.1, -z.1)) (μ.prod ν) (μ.prod ν)