TY  - CHAP
U1  - Konferenzveröffentlichung
A1  - Wartena, Christian
T1  - Extending Linear Indexed Grammars
T2  - Proceedings of the Fifth International Workshop on Tree Adjoining Grammar and Related Frameworks (TAG+5)
N2  - This paper presents a possibility to extend the formalism of linear indexed grammars. The extension is based on the use of tuples of pushdowns instead of one pushdown to store indices during a derivation. If a restriction on the accessibility of the pushdowns is used, it can be shown that the resulting formalisms give rise to a hierarchy of languages that is equivalent with a hierarchy defined by Weir. For this equivalence, that was already known for a slightly different formalism, this paper gives a new proof. Since all languages of Weir's hierarchy are known to be mildly context sensitive, the proposed extensions of LIGs become comparable with extensions of tree adjoining grammars and head grammars.
KW  - Linear Indexed Grammars
KW  - LIG
Y1  - 2000
UN  - https://nbn-resolving.org/urn:nbn:de:bsz:960-opus4-20789
UR  - https://aclanthology.org/W00-2029.pdf
U6  - https://doi.org/10.25968/opus-2078
DO  - https://doi.org/10.25968/opus-2078
SP  - 207
EP  - 214
PB  - Association for Computational Linguistics
ER  -