(motive : Lean.Syntax × Option Lean.Syntax × Option Lean.Elab.Command.Structure.StructFieldViewDefault → Sort u_1) →
  (__discr : Lean.Syntax × Option Lean.Syntax × Option Lean.Elab.Command.Structure.StructFieldViewDefault) →
    ((binders : Lean.Syntax) →
        (type? : Option Lean.Syntax) →
          (default? : Option Lean.Elab.Command.Structure.StructFieldViewDefault) → motive (binders, type?, default?)) →
      motive __discr