English
For any nonzero PadicSeq f, its norm equals p to the power of the negative of its valuation, i.e., f.norm = (p)^{ - valuation(f) }.
Русский
Для любой ненулевой PadicSeq f нормa равна p в степени минус оценки f, то есть f.norm = p^{ - valuation(f) }.
LaTeX
$$$f.norm = p^{ -\mathrm{valuation}(f) }$$$
Lean4
theorem norm_eq_zpow_neg_valuation {f : PadicSeq p} (hf : ¬f ≈ 0) : f.norm = (p : ℚ) ^ (-f.valuation : ℤ) :=
by
rw [norm, valuation, dif_neg hf, dif_neg hf, padicNorm, if_neg]
intro H
apply CauSeq.not_limZero_of_not_congr_zero hf
intro ε hε
use stationaryPoint hf
intro n hn
rw [stationaryPoint_spec hf le_rfl hn]
simpa [H] using hε