English
The modified Euler–Mascheroni sequence eulerMascheroniSeq' converges to γ: lim eulerMascheroniSeq'(n) = γ.
Русский
Пусть eulerMascheroniSeq' сходится к γ: lim eulerMascheroniSeq'(n) = γ.
LaTeX
$$\lim_{n\to\infty} eulerMascheroniSeq'(n) = \gamma$$
Lean4
theorem tendsto_eulerMascheroniSeq' : Tendsto eulerMascheroniSeq' atTop (𝓝 eulerMascheroniConstant) :=
by
suffices Tendsto (fun n ↦ eulerMascheroniSeq' n - eulerMascheroniSeq n) atTop (𝓝 0) by
simpa using this.add tendsto_eulerMascheroniSeq
suffices Tendsto (fun x : ℝ ↦ log (x + 1) - log x) atTop (𝓝 0)
by
apply (this.comp tendsto_natCast_atTop_atTop).congr'
filter_upwards [eventually_ne_atTop 0] with n hn
simp [eulerMascheroniSeq, eulerMascheroniSeq', eq_false_intro hn]
exact tendsto_log_comp_add_sub_log 1