Abstract
We give a new, and hopefully more easily understandable, structural proof of the decomposition of a k-valued transducer into k unambiguous functional ones, a result established by A. Weber in 1996. Our construction is based on a lexicographic ordering of computations of automata and on two coverings that can be build by means of this ordering. The complexity of the construction, measured as the number of states of the transducers involved in the decomposition, improves the original one by one exponential.
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A preliminary version of this paper has been presented at the STACS 2008 conference under the title On the decomposition of k -valued rational relations [20].
A financial support of CAPES Foundation (Brazilian government) for doctoral studies is gratefully acknowledged by R. de Souza.
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Sakarovitch, J., de Souza, R. Lexicographic Decomposition of k-Valued Transducers. Theory Comput Syst 47, 758–785 (2010). https://doi.org/10.1007/s00224-009-9206-6
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DOI: https://doi.org/10.1007/s00224-009-9206-6