fact: Fixpoint mulX v P := match P with | Pconst c => addX c v 0 | PX P1 w P2 => match v ?= w with | LT => PX (mulX v P1) w (mulX v P2) | _ => PX P v 0 end end.
imports: HoTT.Classes.interfaces.abstract_algebra HoTT.Classes.theory.additional_operations HoTT.Classes.tactics.ring_quote HoTT.Classes.theory.rings