English
Interval integrability on [a,b] is equivalent to ordinary integrability of f on the oriented interval Ι(a,b).
Русский
Интервальная интегрируемость по отрезку [a,b] эквивалентна обычной интегрируемости по ориентированному интервалу Ι(a,b).
LaTeX
$$$$\text{IntervalIntegrable}(f,μ,a,b) \iff \text{IntegrableOn}(f,Ι(a,b),μ).$$$$
Lean4
/-- A function is interval integrable with respect to a given measure `μ` on `a..b` if and
only if it is integrable on `uIoc a b` with respect to `μ`. This is an equivalent
definition of `IntervalIntegrable`. -/
theorem intervalIntegrable_iff : IntervalIntegrable f μ a b ↔ IntegrableOn f (Ι a b) μ := by
rw [uIoc_eq_union, integrableOn_union, IntervalIntegrable]