English
Properness is equivalent to continuity plus tendsto along cocompact: Tendsto f (cocompact X) (cocompact Y).
Русский
Пропорность эквивалентна непрерывности и стремлению к кокомпактности: Tendsto f (cocompact X) (cocompact Y).
LaTeX
$$IsProperMap f ↔ Continuous f ∧ Tendsto f (cocompact X) (cocompact Y)$$
Lean4
instance hasLipschitzAdd : LipschitzAdd ℝ≥0 where
lipschitz_add :=
⟨LipschitzAdd.C ℝ, by
rintro ⟨x₁, x₂⟩ ⟨y₁, y₂⟩
exact lipschitzWith_lipschitz_const_add_edist ⟨(x₁ : ℝ), x₂⟩ ⟨y₁, y₂⟩⟩