Computing 2-folded integral

Question

What is the easiest way to assemble matrix in 2D whose elements are defined as:

$$b_{ln} = \int_{\Omega} h_{l}(x) \int_{\Omega} F(x,x_1) h_n(x_1) dx_1 dx$$
$$ F(x,x_1) = e^{(-|x-x_1|-|y-y_1|)}$$

Comments

This has already been addressed in your previous question, no?

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Nate,

but how should I compute for 2D case?