Abstract
We present two new results on 2-collapsing words. First, we show that the language of all 2-collapsing words over 2 letters is not context-free. Second, we prove that the length of a 2-collapsing word over an arbitrary finite alphabet Σ is at least 2|Σ|2 thus improving the previously known lower bound |Σ|2 + 1.
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Pribavkina, E.V. (2005). On Some Properties of the Language of 2-Collapsing Words. In: De Felice, C., Restivo, A. (eds) Developments in Language Theory. DLT 2005. Lecture Notes in Computer Science, vol 3572. Springer, Berlin, Heidelberg. https://doi.org/10.1007/11505877_33
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DOI: https://doi.org/10.1007/11505877_33
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-26546-7
Online ISBN: 978-3-540-31682-4
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