English
The fract function tends to 1 as x approaches from left to integers, and to 0 as x tends to infinity.
Русский
fract стремится к 1 слева от целых чисел, и к 0 при возрастании x.
LaTeX
$$$$\text{Tendsto}(\operatorname{fract}, x^-\to 1, x^+\to 0)$$$$
Lean4
theorem tendsto_fract_left [OrderClosedTopology α] [IsTopologicalAddGroup α] (n : ℤ) :
Tendsto (fract : α → α) (𝓝[<] n) (𝓝[<] 1) :=
tendsto_nhdsWithin_of_tendsto_nhds_of_eventually_within _ (tendsto_fract_left' _) (Eventually.of_forall fract_lt_one)