Sorry about acc=10^{-3}. I just mistakenly wrote here in that form.

Thanks. Yes, I know I can define it locally instead of loading the package. As it is available, I am just loading that for instance. Additionally, that won't solve my problem. All I want is to stop the iteration at some fix accuracy.

I was looking into the previous 'integral-equation' questions and found that my problem is similar to a previously asked unsolved question (mathematica.stackexchange.com/questions/21303/…). In that question, mathematica.stackexchange.com/users/193/dr-belisarius commented that s/he knew the answer but didn't have time. I'll really appreciate if Dr. Belisarius can help me and answer this.