fact: Definition POneSubst (P1: Pol) (M1: Mon) (P2: Pol): option Pol := let (Q1,R1) := MFactor P1 M1 in match R1 with (Pc c) => if c ?=! cO then None else Some (Padd Q1 (Pmul P2 R1)) | _ => Some (Padd Q1 (Pmul P2 R1)) end.
imports: Setoid Morphisms Env BinPos BinNat BinInt Ring_theory