function bsbracket
% bsbracket Print current binary search bracket [PHYS210-bs]
   global Bs_low Bs_high Bs_tol Bs_progress;
   if ~ bsinitialized
      warning('Search not initialized.  Use bsnew(low, high)');
      return;
   end
   fprintf('%.16e\n%.16e\n', Bs_low(end), Bs_high(end));
end
