∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] (X : C) [inst_1 : CategoryTheory.Limits.HasBinaryProducts C]
  {X_1 Y : CategoryTheory.Over X} (g : X_1 ⟶ Y), ((CategoryTheory.overToCoalgebra X).map g).f = g.left