Why it matters: Musk helped found OpenAI in 2015 but has since become a bitter opponent and critic of the ChatGPT maker.

The big picture: Friday's filing is the latest salvo in a high profile legal battle pitting the AI revolution's standard-bearing company against president-elect Trump's closest tech adviser. Musk is also the founder of xAI, an OpenAI rival.

Driving the news: OpenAI's new court filing includes a number of e-mails between Musk (and his representatives) and other OpenAI co-founders, including Altman and Ilya Sutskever.

What they're saying: "Elon Musk's latest legal filing against OpenAI marks his fourth attempt in less than a year to reframe his claims," OpenAI said in a blog post. "However, his own words and actions speak for themselves -- in

2017, Elon not only wanted, but actually created, a for-profit as OpenAI's proposed new structure."

What they're saying: In Sept. 2017, Sutskever sent Musk -- along with Altman and co-founder Greg Brockman -- an email rejecting Musk's terms.

Yes, but: The new emails are presented in an OpenAI blog post without full context.