∀ {T : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} T] {P : CategoryTheory.MorphismProperty T} {X Y Z : T}
  (f : X ⟶ Y) (g : Y ⟶ Z) [P.IsStableUnderBaseChangeAlong f] [P.IsStableUnderBaseChangeAlong g]
  [CategoryTheory.Limits.HasPullbacks T] (fg : optParam (X ⟶ Z) (CategoryTheory.CategoryStruct.comp f g)),
  autoParam (CategoryTheory.CategoryStruct.comp f g = fg)
      CategoryTheory.MorphismProperty.Over.pullbackMapHomPullback._auto_1 →
    P.IsStableUnderBaseChangeAlong fg