fact: Definition ww_sub x y := match y, x with | W0, _ => x | WW yh yl, W0 => ww_opp (WW yh yl) | WW yh yl, WW xh xl => match w_sub_c xl yl with | C0 l => w_WW (w_sub xh yh) l | C1 l => WW (w_sub_carry xh yh) l end end.
imports: ZArith Lia BigNumPrelude DoubleType DoubleBase