(motive : Option (Array (Lean.TSyntax `Lean.Parser.Tactic.tacticSeq)) → Sort u_1) →
  (x : Option (Array (Lean.TSyntax `Lean.Parser.Tactic.tacticSeq))) →
    ((tacs : Array (Lean.TSyntax `Lean.Parser.Tactic.tacticSeq)) → motive (some tacs)) → (Unit → motive none) → motive x