∀ {G : Type u} {α : Type w} {m : MeasurableSpace α} [inst : AddGroup G] [inst_1 : AddAction G α]
  (μ : MeasureTheory.Measure α) [MeasureTheory.VAddInvariantMeasure G α μ] (c : G) (s t : Set α),
  μ (symmDiff (-c +ᵥ s) t) = μ (symmDiff s (c +ᵥ t))