"i ⇌ o / a?[c-d-g-k-l-r-s-t-z]?[a-e-o][c-e-g-k-ē][s-t]_s" . . . "i ⇌ o / a?[c-d-g-k-l-r-s-t-z]?[a-e-o][c-e-g-k-ē][s-t]_s" . .