import scala.concurrent._

import scala.concurrent.duration._

import ExecutionContext.Implicits.global

import scala.language.postfixOps 

import scala.language.reflectiveCalls

lazy val f = Future {

  import CW8a._

  val EVIL_urban = SEQ(STAR(STAR(CHAR('a'))), CHAR('b'))

  assert(size(der('a', der('a', EVIL_urban))) == 28)

  assert(size(der('a', der('a', der('a', EVIL_urban)))) == 58)

  assert(size(ders("aaaaaa".toList, EVIL_urban)) == 8)

}

Await.result(f, 120 second)