{C : Type u} →
  {inst : CategoryTheory.Category.{v, u} C} →
    {P : Sort u_1} →
      {weakEquivalences weakEquivalences' : CategoryTheory.MorphismProperty C} →
        { weakEquivalences := weakEquivalences } = { weakEquivalences := weakEquivalences' } →
          (weakEquivalences ≍ weakEquivalences' → P) → P