def urbanmain() = {
  import M3._

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

  assert(ders(("a" * 5).toList, EVIL_urban) == SEQs(List(STAR(CHAR('a')), STAR(STAR(CHAR('a'))), CHAR('b'))))
  assert(ders(List('b'), EVIL_urban) == ONE)
  assert(ders(List('b','b'), EVIL_urban) == ZERO)
  assert(matcher(EVIL_urban, "a" * 5 ++ "b") == true)
  assert(matcher(EVIL_urban, "a" * 50 ++ "b") == true)
  assert(matcher(EVIL_urban, "a" * 50) == false)
  assert(matcher(EVIL_urban, "b") == true)
  assert(matcher(EVIL_urban, "bb") == false)
  assert(matcher("abc", "abc") == true)
  assert(matcher("abc", "ab") == false)
  assert(matcher(("ab" | "a") ~ (ONE | "bc"), "abc") == true)
  assert(matcher(ONE, "") == true)
  assert(matcher(ZERO, "") == false)
  assert(matcher(ONE | CHAR('a'), "") == true)
  assert(matcher(ONE | CHAR('a'), "a") == true)
}