> These are the regular genitive singular for stems in vocalic -r.,Thanks for the information. :)
> e.g. da:tr. "giver" has gen sing da:tuh. The only anomaly in the
> father/mother declension is that the accusative plural of feminines
> is not -r.:n but -r.:h. Both accustives, however, clearly go back
> to an original PIE ending -ns, which survives in sandhi. the gen
> sing goes back, as you say, to -rs.