∀ {R : Type uR} [inst : Semiring R] (r : R → R → Prop) {a b : R},
  { toQuot := Quot.mk (RingQuot.Rel r) a } * { toQuot := Quot.mk (RingQuot.Rel r) b } =
    { toQuot := Quot.mk (RingQuot.Rel r) (a * b) }