Diachronically, when an allative loses its local meaning (or acquires additional, non-local meanings), it will become a dative (expressing beneficiary and/or indirect object); when a locative loses its local meaning (or acquires additional, non-local meanings), it will become an accusative or ergative; when an ablative loses its local meaning (or acquires additional, non-local meaning)s, it will become a (partitive) genitive or ergative or (passive) agentive.
Standardized
Diachronically, when an allative loses its local meaning (or acquires additional, non-local meanings), it will become a dative (expressing beneficiary and/or indirect object); when a locative loses its local meaning (or acquires additional, non-local meanings), it will become an accusative or ergative; when an ablative loses its local meaning (or acquires additional, non-local meaning)s, it will become a (partitive) genitive or ergative or (passive) agentive.
