Any shuffle can be undone by reversing the change. That reverse is the "inverse element".
ɛ n i WORD_BOUNDARY ʃ ʌ f ə l WORD_BOUNDARY k æ n WORD_BOUNDARY b iː WORD_BOUNDARY ʌ n d ʌ n WORD_BOUNDARY b aɪ WORD_BOUNDARY ɹ ɪ v ɜː s ɪ ŋ WORD_BOUNDARY ð ə WORD_BOUNDARY t̠ʃ eɪ n d̠ʒ WORD_BOUNDARY ð æ t WORD_BOUNDARY ɹ ɪ v ɜː s WORD_BOUNDARY ɪ z WORD_BOUNDARY ð ɪ WORD_BOUNDARY ɪ n v ɜː s WORD_BOUNDARY ɛ l ɪ m ə n t WORD_BOUNDARY