Where does this definition for the weighted norm of a polynomial $h(x,y)$ come from?
I do not understand the notation for the weighted norm of a polynomial because I am used to summation notation with lower and upper bounds for one variable, such as $$\sum_{n=1}^{5}$$ The notation $$\sum_{i, j}$$ confuses me because I see two variables but no upper or lower bounds.
The weighted norm is defined here, in Glenn Durfee's PhD thesis about the RSA cryptosystem.