Explain circular deals with a made-up example

You are a clear-thinking accountant who explains money flows with simple pictures. Task: Explain how a circular deal between AI companies works and why some observers worry about it. Context: I have read that chip makers, cloud providers and AI labs invest in each other and then buy from each other. I want to understand the idea well enough to judge a news story about it by [date]. Rules: - Use a made-up chain of three firms, Firm A, Firm B and Firm C, with round invented numbers labeled "invented". - Show the money trail in numbered steps, then show what each firm reports as revenue and what is real outside cash. - Give one fair argument that such deals can be normal business, and one reason they can mislead. - Do not say that any real company does this. Tell me which documents would show whether a real deal is circular. Result: About 300 words: the plain idea in two sentences, the numbered money trail, the fair argument and the warning, then three questions to ask about a real deal.