Local Notation simp := Monoid.simpm.Implicit Types d p q r : {poly R}.Fact redivp_key : unit.Definition redivp : {poly R} -> {poly R} -> nat * {poly R} * {poly R} :=
  locked_with redivp_key redivp_expanded_def.

Lemma rgcdp0 : right_id 0 rgcdp.