fact: Fixpoint PaddI (j:positive) (P:Pol) : Pol := match P with | Pc c => mkPinj j (PaddC Q c) | Pinj j' Q' => match Z.pos_sub j' j with | Zpos k => mkPinj j (Pop (Pinj k Q') Q) | Z0 => mkPinj j (Pop Q' Q) | Zneg k => mkPinj j' (PaddI k Q') end | PX P i Q' => match j with | xH => PX P i (Pop Q' Q) | xO j => PX P i (PaddI (Pos.pred_double j) Q') | xI j => PX P i (PaddI (xO j) Q') end end.
imports: Setoid Morphisms BinList BinPos BinNat BinInt Ring_theory