(SetTheory.PGame.nim 1).Relabelling SetTheory.PGame.star =
  (SetTheory.PGame.mk (Ordinal.ToType 1) (Ordinal.ToType 1) (fun x => SetTheory.PGame.nim ↑x.toOrd) fun x =>
        SetTheory.PGame.nim ↑x.toOrd).Relabelling
    SetTheory.PGame.star