mr. brownell.agency at that point in time was only answering the very first question, the very threshold issue. at that point, the agency said cost were irrelevant. but cost become irrelevant leader in the analysis and in a variety of ways. through the 12 and a half percent, through the 12% through the categorization of sub categorization, through the determination whether to raise standards even higher. so costs costs later, but as to this reticular thing, the agency said yes here we don't consider costs. we could, what we don't want to because there is all this potential for cost to come in afterwards. mr. brownell: and your honor, it's costs cost costs under the statutory criteria that congress provided for setting control technology standards and then having to find their standards at the end of the process. the agency finalizes its determination in light of the costs and impacts and other factors entered in the -- justice kennedy: do you think whenever the term "appropriate" is used in the cle