∀ {O : Type u_1} [inst : CommRing O] {p : ℕ} [inst_1 : Fact (Nat.Prime p)] [inst_2 : Fact ¬IsUnit ↑p]
  [inst_3 : IsAdicComplete (Ideal.span {↑p}) O],
  ⇑(Ideal.Quotient.mk (Ideal.span {↑p})) ∘ ⇑PreTilt.untilt = ⇑(PreTilt.coeff 0)