simp only [triangleQPA₂, Matrix.range_cons, Matrix.range_empty, Set.singleton_union,
  insert_emptyc_eq]
case refine_2
V : Type u_1
Pt : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace Pt
inst✝ : NormedAddTorsor V Pt
hd2 : Fact (finrank ℝ V = 2)
cfg : Imo2019q2Cfg V Pt
⊢ Set.range cfg.triangleQPA₂.points ⊆ {cfg.Q, cfg.P, cfg.B₂, cfg.A₂}
case refine_2
V : Type u_1
Pt : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace Pt
inst✝ : NormedAddTorsor V Pt
hd2 : Fact (finrank ℝ V = 2)
cfg : Imo2019q2Cfg V Pt
⊢ {cfg.Q, cfg.P, cfg.A₂} ⊆ {cfg.Q, cfg.P, cfg.B₂, cfg.A₂}