English
Exponentials dominate polynomial-type z^m with z^m when exponents are compared.
Русский
Экспоненты доминируют над полиномиальным видом z^m при сравнении степеней.
LaTeX
$$$\\forall {b_1 b_2 : \\mathbb{R}},\\; (hb: b_1 < b_2) \\to \\forall {m n : \\mathbb{Z}},\\; (z \\mapsto z^m e^{b_1 z}) =o_l (z \\mapsto z^n e^{b_2 z})$$$
Lean4
/-- `log` is analytic away from nonpositive reals -/
@[fun_prop]
theorem analyticAt_clog (m : z ∈ slitPlane) : AnalyticAt ℂ log z :=
by
rw [analyticAt_iff_eventually_differentiableAt]
filter_upwards [isOpen_slitPlane.eventually_mem m]
intro z m
exact differentiableAt_id.clog m