(motive : Mathlib.Notation3.DelabKey → Sort u_1) →
  (key : Mathlib.Notation3.DelabKey) →
    ((const : Option Lean.Name) → (arity : ℕ) → motive (Mathlib.Notation3.DelabKey.app const arity)) →
      ((x : Mathlib.Notation3.DelabKey) → motive x) → motive key