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