The discussion revolves around proving that an increasing function defined on the real numbers is Riemann integrable over any interval. The original poster expresses uncertainty about how to approach the proof, despite being aware of its validity based on references from other texts.
The conversation is ongoing, with some participants providing guidance on how to approach the proof. There is an acknowledgment of previous knowledge regarding the theorem, but no consensus has been reached on the specific steps to take.
Participants reference the concept of functions being continuous almost everywhere and the measure of countable sets, indicating that these ideas are central to the discussion. The original poster's uncertainty suggests that they may be grappling with the application of these concepts in their proof.
