English
For any x in ℤ_p, (x : ℚ_p) = 0 iff x = 0.
Русский
Для любого x ∈ ℤ_p, (x : ℚ_p) = 0 тогда и только тогда, когда x = 0.
LaTeX
$$$(x : \mathbb{Q}_p) = 0 \iff x = 0$$$
Lean4
/-- A sequence of integers that is Cauchy with respect to the `p`-adic norm converges to a `p`-adic
integer. -/
def ofIntSeq (seq : ℕ → ℤ) (h : IsCauSeq (padicNorm p) fun n => seq n) : ℤ_[p] :=
⟨⟦⟨_, h⟩⟧,
show ↑(PadicSeq.norm _) ≤ (1 : ℝ) by
rw [PadicSeq.norm]
split_ifs with hne <;> norm_cast
apply padicNorm.of_int⟩