INTRICACIES OF SIMPLE WORD EQUATIONS: AN EXAMPLE
Elena Czeizler, Štěpán Holub, Juhani Karhumäki, Markku Laine · International Journal of Foundations of Computer Science · 2007
As is well known, simple word equations can be very tedious to solve, often requiring specific ad hoc methods. We illustrate this by giving an example of an equation over four unknowns, having only periodic solutions, but for which showing this is not at all obvious.