fact: Fixpoint Ppow_pos (res P:Pol) (p:positive) : Pol := match p with | xH => subst_l (res ** P) | xO p => Ppow_pos (Ppow_pos res P p) P p | xI p => subst_l ((Ppow_pos (Ppow_pos res P p) P p) ** P) end.
imports: Setoid Morphisms BinList BinPos BinNat BinInt Ring_theory