Abstract
We prove connections between one-unknown word equations and three-unknown constant-free word equations, and use them to prove that the number of equations in an independent system of three-unknown constant-free equations is at most logarithmic with respect to the length of the shortest equation in the system. We also study two well-known conjectures. The first conjecture claims that there is a constant c such that every one-unknown equation has either infinitely many solutions or at most c. The second conjecture claims that there is a constant c such that every independent system of three-unknown constant-free equations with a nonperiodic solution is of size at most c. We prove that the first conjecture implies the second one, possibly for a different constant.
This work has been supported by the DFG Heisenberg grant 590179 (Dirk Nowotka), the DFG research grant 614256 and the Vilho, Yrjö and Kalle Väisälä Foundation (Aleksi Saarela).
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Nowotka, D., Saarela, A. (2016). One-Unknown Word Equations and Three-Unknown Constant-Free Word Equations. In: Brlek, S., Reutenauer, C. (eds) Developments in Language Theory. DLT 2016. Lecture Notes in Computer Science(), vol 9840. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-53132-7_27
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DOI: https://doi.org/10.1007/978-3-662-53132-7_27
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