## Summary After #13918 has landed, narrowing constraint negation became easy, so adding support for `not` operator. ## Test Plan Added a new mdtest file for `not` expression. --------- Co-authored-by: Carl Meyer <carl@astral.sh>
Markdown files within the mdtest/ subdirectory are tests of type inference and type checking;
executed by the tests/mdtest.rs integration test.
See crates/red_knot_test/README.md for documentation of this test format.