(motive : Option (Array (Lean.TSyntax `Lean.Parser.Term.letRecDecl)) → Sort u_1) →
  (x : Option (Array (Lean.TSyntax `Lean.Parser.Term.letRecDecl))) →
    ((letRecDecls : Array (Lean.TSyntax `Lean.Parser.Term.letRecDecl)) → motive (some letRecDecls)) →
      (Unit → motive none) → motive x