he+eh sama he+eh
he eh sama he eh .
h ɛ WORD_BOUNDARY  ɛ h WORD_BOUNDARY s a m a WORD_BOUNDARY h ɛ WORD_BOUNDARY  ɛ h WORD_BOUNDARY
h e WORD_BOUNDARY e h WORD_BOUNDARY s a m a WORD_BOUNDARY h e WORD_BOUNDARY e h WORD_BOUNDARY