| other,15-1-J89-4003,ak | adding <term> reduplication </term> to <term> | context-free languages | </term> . The model is a <term> pushdown automaton | #20110 A model is presented to characterize the class of languages obtained by adding reduplication to context-free languages . | |
| other,12-3-J89-4003,ak | shown to lie strictly between the <term> | context-free languages | </term> and the <term> indexed languages </term> | #20147 The class of languages generated is shown to lie strictly between the context-free languages and the indexed languages. | |
| other,17-4-J89-4003,ak | that have been observed to occur in <term> | natural languages | </term> , but it excludes many of the unnatural | #20171 The model appears capable of accommodating the sort of reduplications that have been observed to occur in natural languages , but it excludes many of the unnatural constructions that other formal models have permitted. |
