Coming-to-be is a change where the substrate of the thing that has undergone the change has itself changed.
kˈʌmɪŋtəbi ɪz ɐ tʃˈeɪndʒ wˌɛɹ ðə sˈʌbstɹeɪt ʌvðə θˈɪŋ ðæt hɐz ˌʌndɚɡˈɑːn ðə tʃˈeɪndʒ hɐz ɪtsˈɛlf tʃˈeɪndʒd.