fact: Definition mkPX P i n Q := match P with | Pc c => if c =? 0 then Q else PX P i n Q | PX P' i' n' Q' => match Pos.compare i i' with | Eq => if Q' =? P0 then PX P' i (n + n') Q else PX P i n Q | _ => PX P i n Q end end.
imports: Setoid BinList BinPos BinNat BinInt Ring_polynom Ncring