s e t t s
s e t t s
n:let n:let n:let n:let n:let
s e t t s .
ɛ s WORD_BOUNDARY iː WORD_BOUNDARY t iː WORD_BOUNDARY t iː WORD_BOUNDARY ɛ s WORD_BOUNDARY
s WORD_BOUNDARY e WORD_BOUNDARY t WORD_BOUNDARY t WORD_BOUNDARY s WORD_BOUNDARY