Polynomial Charts for Totally Unordered Languages

Proceedings of the 16th Nordic Conference of Computational Linguistics NODALIDA-2007. Editors: Joakim Nivre, Heiki-Jaan Kaalep, Kadri Muischnek and Mare Koit. University of Tartu, Tartu, 2007. ISBN 978-9985-4-0513-0 (online) ISBN 978-9985-4-0514-7 (CD-ROM) pp. 183-190

Bounded Length UCFG Equivalence

. A randomised polylog time algorithm is given for deciding whether or not the sets of words of a given length generated by two unambiguous context-free grammars coincide. The algorithm is in randomised NC4 in terms of the product of the grammar size and the length.