u2 u2 u2 u2 u2
u2 u2 u2 u2 u2
sfp sfp sfp sfp sfp
u2 u2 u2 u2 u2 .
u˨˥ WORD_BOUNDARY u˨˥ WORD_BOUNDARY u˨˥ WORD_BOUNDARY u˨˥ WORD_BOUNDARY u˨˥ WORD_BOUNDARY
u 2 WORD_BOUNDARY u 2 WORD_BOUNDARY u 2 WORD_BOUNDARY u 2 WORD_BOUNDARY u 2 WORD_BOUNDARY . WORD_BOUNDARY