Lean

https://lean-lang.org/

Lean is a functional programming language that makes it easy to write correct and maintainable code. You can also use Lean as an interactive theorem prover. Lean programming primarily involves defining types and functions. This allows your focus to remain on the problem domain and manipulating its data, rather than the details of programming

• Here's a post by Terence Tao describing how he used lean to prove a theorem, with further details in part 2