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