@dang, pleaaase can we get proper markdown formatting on HN? I tried adding two spaces after each line, but I don't want paragraphs between code
The inversion is really cool, e.g.
> f = λa λb concat ["Hello ", a, " ", b, "!"]
> f "Jane" "Doe"
Hello Jane Doe!
> g = f "Admiral"
> invert g "Hello Admiral Alice!"
Alice