Try doing some basic maths questions in the Lean Theorem Prover. Functions, real numbers, equivalence relations and groups. Click on README.md and then on "Open in CoCalc with one click".
License: APACHE
-- Print the current version of lean, using logic copied from leanpkg.
import system.io
def lean_version_string_core :=
let (major, minor, patch) := lean.version in
sformat!("{major}.{minor}.{patch}")
def main : io unit :=
io.put_str_ln lean_version_string_core