The universal generation problem for LFG grammars is the problem of determining whether a given grammar derives any terminal string with a given f-structure. It is known that this problem is decidable for acyclic f-structures. In this brief note, we show that for those f-structures the problem is nonetheless intractable. This holds even for grammars that are off-line parsable.

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Author notes


Department of Nordic Studies and Linguistics, Emil Holms Kanal 2, 2300 Copenhagen S, Denmark. E-mail: jwedekind@hum.ku.dk.


Linguistics Department,Margaret Jacks Hall Building 460, Stanford, CA 94305, USA. E-mail: rmkaplan@stanford.edu.

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