∀ {G : Type u_1} {X : Type u_3} [inst : TopologicalSpace X] [inst_1 : TopologicalSpace G] [inst_2 : Neg G]
  [ContinuousNeg G] {f : X → G} {s : Set X} {x : X}, ContinuousWithinAt f s x → ContinuousWithinAt (fun x => -f x) s x