∀ {C : Type u_1} {ι : Type u_2} {c : ComplexShape ι} [inst : CategoryTheory.Category.{v_1, u_1} C]
  [inst_1 : CategoryTheory.Limits.HasZeroMorphisms C] [inst_2 : CategoryTheory.Limits.HasZeroObject C]
  [inst_3 : DecidableEq ι] (i j : ι) (P : C) [CategoryTheory.Projective P],
  CategoryTheory.Projective (((HomologicalComplex.single C c i).obj P).X j)