>Do I think it is possible to produce zero-bug software? Yes, I do,

I disagree, and so does the rest of the professional software testing industry. You can hit a piece of code 10K times, and it may be the 10K+1th time that it fails. You can do code coverage and think that a piece of code is unreachable, but your customer will find a permutation that reachs that code. In a complex system, there are enough possible permutations that you could spend a lifetime testing it.