"sī ⇌ turum / [-spread]*[+son][b-c-d-g-k-l-m-n-p-q-r-s-t-z]_" . . . "sī ⇌ turum / [-spread]*[+son][b-c-d-g-k-l-m-n-p-q-r-s-t-z]_" . .