An Algorithm for Deciding the Summability of Bivariate Rational Functions

Qing-Hu Hou, Rong-Hua Wang

Let ${\Delta }_{x}f(x,y)=f(x+1,y)-f(x,y)$ and ${\Delta }_{y}f(x,y)=f(x,y+1)-f(x,y)$ be the difference operators with respect to $x$ and $y$. A rational function $f(x,y)$ is called summable if there…