Ko e meʻalele fika 0 ʻi he fakatātaá ko hoʻo meʻalele. ʻOkú ke afe toʻomataʻu mei ha feituʻu tatali ʻo kolosi ʻi ha laine fehangahangai ʻe 2 ki ha hala fakatafaʻaki. ʻOku ʻalu hangatonu ʻa e X ʻi ha laine fehangahangai ʻe taha; ʻoku afe toʻohema ʻa e loli Y mei he laine ʻe tahá ki he hala fakatafaʻaki ko ia. ʻOku tatali ʻa e Z ʻi ha STOP ʻi he hala fakatafaʻaki. Ko hai kuo pau ke ke tukuange ʻa e hala ki ai? ʻOku ʻikai ha papa, maama pe tuʻutuʻuni polisi kehe ʻoku liliu ʻa e totonu ke muʻomuʻa kuo fakamatalaʻi.