def urbanmain() = {

  import M3._

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


  assert(simp(Iterator.iterate(ONE:Rexp)(r => SEQ(r, ONE | ONE)).drop(50).next) == ONE)
  assert(simp(Iterator.iterate(ONE:Rexp)(r => ALT(r, r)).drop(20).next) == ONE)
  assert(matcher(EVIL_urban, "a" * 1000000) == false)
  assert(matcher(EVIL_urban, "a" * 1000000 ++ "b") == true)
}