{P : Sort u} →
  {fieldViews : Array Lean.Elab.Term.StructInst.FieldView} →
    {sources : Array Lean.Elab.Term.StructInst.ExplicitSourceView} →
      {fieldViews' : Array Lean.Elab.Term.StructInst.FieldView} →
        {sources' : Array Lean.Elab.Term.StructInst.ExplicitSourceView} →
          Lean.Elab.Term.StructInst.ExpandedFieldVal.nested✝ fieldViews sources =
              Lean.Elab.Term.StructInst.ExpandedFieldVal.nested✝¹ fieldViews' sources' →
            (fieldViews = fieldViews' → sources = sources' → P) → P