fact: Definition ww_mul x y := match x, y with | W0, _ => W0 | _, W0 => W0 | WW xh xl, WW yh yl => let ccl := w_add (w_mul xh yl) (w_mul xl yh) in ww_add (w_W0 ccl) (w_mul_c xl yl) end.
imports: ZArith Lia BigNumPrelude DoubleType DoubleBase