Equivalence of Definitions of Convergent P-adic Sequence

Theorem
Let $p$ be a prime number.

Let $\struct {\Q_p, \norm {\,\cdot\,}_p}$ be the $p$-adic numbers.

Let $\sequence {x_n} $ be a sequence in $\Q_p$.

Proof
From P-adic Numbers form Non-Archimedean Valued Field:
 * the $p$-adic norm is the norm on a division ring.

By definition, the $p$-adic metric is the metric induced by the $p$-adic norm.

From Equivalence of Definitions of Convergence in Normed Division Rings, it follows that Definition 2, Definition 3 and Definition 4 are equivalent.

By definition of convergence in a normed division ring, $\sequence {x_n}$ converges to $x$ in the $p$-adic norm :
 * $\forall \epsilon \in \R_{>0}: \exists N \in \R_{>0}: \forall n \in \N: n > N \implies \norm {x_n - x}_p < \epsilon$

So Definition 1 is equivalent to Definition 2.