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Random Generation for FinitelyAmbiguous Context-free Languages

Published online by Cambridge University Press:  15 July 2002

Alberto Bertoni
Dipartimento di Scienze dell'Informazione, Università degli Studi di Milano, via Comelico 39/41, 20135 Milano, Italy; (
Massimiliano Goldwurm
Dipartimento di Scienze dell'Informazione, Università degli Studi di Milano, via Comelico 39/41, 20135 Milano, Italy; (
Massimo Santini
Dipartimento di Scienze Sociali, Cognitive e Quantitative, Università degli Studi di Modena e Reggio Emilia, Via Giglioli Valle, 42100 Reggio Emilia, Italy; (
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We prove that a word of length n from a finitely ambiguous context-free language can be generated at random under uniform distribution in O(n2 log n) time by a probabilistic random access machine assuming a logarithmic cost criterion. We also show that the same problem can be solved in polynomial time for every language accepted by a polynomial time 1-NAuxPDA with polynomially bounded ambiguity.


Research Article
© EDP Sciences, 2001

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