Hello all, I'm working through a majority of the problems in "A First Course in Wavelets with Fourier Analysis" and have stumbled upon a problem I'm having difficulty with. Please view the PDF attachment, it shows the problem and what I have done with it so far. Once you have seen the problem and my work so far, what do you suggest I do for the next step? I thought about using the definition of the space D and setting everything less than or equal to the double integral of 1^(j+k_/2, which is just the double integral of 1 and you get xy, then I'm at a dead end, so perhaps that's not the correct route. Your ideas would be greatly appreciated.