Indexed Languages and Unification Grammars
<|reference_start|>Indexed Languages and Unification Grammars: Indexed languages are interesting in computational linguistics because they are the least class of languages in the Chomsky hierarchy that has not been shown not to be adequate to describe the string set of natural language sentences. We here define a class of unification grammars that exactly describe the class of indexed languages.<|reference_end|>
@article{burheim1995indexed,
    title={Indexed Languages and Unification Grammars},
    author={Tore Burheim (University of Bergen)},
    journal={arXiv preprint arXiv:cmp-lg/9507013},
    year={1995},
    archivePrefix={arXiv},
    eprint={cmp-lg/9507013},
    primaryClass={cmp-lg cs.CL}
}