standard of self-has proved difficult to administer and that is relevant to the analysis. and i want to give you an opportunity to respond. >> yes, your honor. the first point i'd like to make is the undue burden test is not at issue in this case. that is the test that applies to regulations, not prohibitions. and the state has conceded that this is a prohibition. that's the title of this law. an act to prohibit abortion after 15 weeks. the only thing at issue in this case is the viability line, and the viability line has been enduringly workable. the lower federal courts have applied it consistently and uniformly for 50 years, and the fifth circuit here below had no difficulty striking down this law unanimously, 3 -0. it's been an exceedingly workable standard. if i may return to your question, sir chief justice, a reasonable possibility standard would not be workable. it would ultimately boil down to an argument that states can prohibit a category of women