- To prove ⟹
consider L(f)−2ϵ<L(f;P) and
U(f;P)<U(f)+2ϵ
- To prove ⟸
consider L(f;P)<L(f) and U(f)<U(f;P)
f:[a,b]→R is integrable on [a,b] when:
- The set of points of discontinuity of a bounded function f is finite.
- The set of points of discontinuity of a bounded function f is finite number
of limit points. (may have infinite number of discontinuities)
In these cases, the discontinuities don’t affect the result of the integration.