Z3 became the world champion in automated theorem-prover competitions.

“Z3 was quite powerful. It caught lots of bugs and saved Microsoft hundreds of millions of dollars in the early 2000s. Leo, though, following the great success of Z3, not just for Microsoft, but, like, he and his collaborator entered it into these automated theorem prover comp- competitions where all the ATPs from all over the world come together, and they're given a bunch of problems and a set amount of time, and whichever ATP can kind of correctly prove true or false for those problems, uh, most accurately wins.”

“Z3 was the world champion at. So he essentially had climbed to the top of the automated theorem prover mountain. But he also was disfa- dissatisfied with the, kind of the fundamental limitations of automated theorem prover technology.”