1 import M3._ 

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

     3 

     4 assert(size(der('a', der('a', EVIL_urban))) == 36)

     5 assert(size(der('a', der('a', der('a', EVIL_urban)))) == 83)

     6 

     7 assert(size(ders("aaaaaa".toList, EVIL_urban)) == 7)

     8 assert(size(ders(("a" * 50).toList, EVIL_urban)) == 7)