English
For any α, [TopologicalSpace α], and f: α → ℝ≥0, the map a ↦ (f(a) : ENNReal) is continuous iff f is continuous.
Русский
Для любого α с топологией и функций f: α → ℝ≥0, отображение a ↦ (f(a) как ENNReal) непрерывно тогда и только когда f непрерывна.
LaTeX
$$$\\bigl( \\operatorname{Continuous}\\bigl( a \\mapsto (f(a)) : \\mathbb{R}_{\\ge 0}^{\\infty} \\bigr) \\bigr) \\iff \\operatorname{Continuous}(f)$$$
Lean4
theorem continuous_coe_iff {α} [TopologicalSpace α] {f : α → ℝ≥0} : (Continuous fun a => (f a : ℝ≥0∞)) ↔ Continuous f :=
isEmbedding_coe.continuous_iff.symm