摘要：Recently there has been some interest in difference equations and systems whose forms resemble some trigonometric formulas. One of the classes of such systems is the so-called hyperbolic-cotangent class of systems of difference equations. The corresponding two-dimensional class has two delays denoted by k and l. So far the class has been studied for the case $k\ne l$ , and it was shown that it is practically solvable when $\max \{k,l\}\le 2$ . In this note we show practical solvability of the system in the case $k=l$ , not only for small values of k and l, but for all $k=l\in {\mathbb {N}}$ , which is the first result of such generality.
关键词：System of difference equations; Solvable systems; Practical solvability
