(motive : Option (Array (Lean.TSyntax `Lean.guardMsgsSpecElt)) → Sort u_1) →
  (x : Option (Array (Lean.TSyntax `Lean.guardMsgsSpecElt))) →
    ((elts : Array (Lean.TSyntax `Lean.guardMsgsSpecElt)) → motive (some elts)) → (Unit → motive none) → motive x