S. initial [sm], [sn] became nasals [m], [n]; [sm-|sn-] > [m-|n-]

Reference ✧ PE19/079.17031

Phonetic Rule Elements

[sm-] > [m-] ✧ PE19/079.17033 (sm > m; initially)
[sn-] > [n-] ✧ PE19/079.17035 (sn > n; initially)