additional $7 million to $10 million to the completion cost. the same document calls it the single string of casing the best economic case for bp. and the conclusion i draw from these documents is that bp used a more dangerous well design to save $7 million. what do you think about that? what's your response? >> i believe that document also highlights that the long-term integrity of the well would best be served by a long string. the long string is not an unusual well design in the gulf of mexico. as i understand -- >> say that again. >> the long string is not an unusual design in the gulf of mexico. >> well, as i understand mr mr. halliburton's witness who was interviewed by our staff, is only 2% to 10% of those wells might use this particular string. a fellow from exxon mobil and