> Many of the world’s leading researchers believe that A.I. will soon be powerful enough to improve itself with little or no help from human developers.

> “A.I. is code. And now, A.I. can code,” a veteran researcher, Richard Socher, said. “The ingredients are there.”

> Dr. Socher recently founded, with seven other researchers, a company to pursue this mind-bending goal, which is often called “recursive self-improvement.”

> His start-up, Recursive Superintelligence, has raised more than $650 million from venture capital firms including Google Ventures and Greycroft and the chip-making giants Nvidia and AMD. The six-month-old company, which has offices in San Francisco and London, has fewer than 30 employees. But it is now valued at more than $4 billion.