∀ {R : Type u_1} {V : Type u_2} {P : Type u_4} [inst : Ring R] [inst_1 : PartialOrder R] [inst_2 : AddCommGroup V]
  [inst_3 : Module R V] [inst_4 : AddTorsor V P] [IsOrderedRing R] {p₁ p₂ p₃ : P},
  List.Sbtw R [p₁, p₂, p₃] = Sbtw R p₁ p₂ p₃