"_ ⇌ s_um / [b-d-e-m-n-p-s-t-z-ē]*[b-d-e-i-m-n-r-y-z-ē-ī]?[-long]_s_" . . . "_ ⇌ s_um / [b-d-e-m-n-p-s-t-z-ē]*[b-d-e-i-m-n-r-y-z-ē-ī]?[-long]_s_" . .