You are not going to spoil that much with an example yielding 2 or 3, especially due to the meeting difficulty being linked to nested brackets.

The random tests call your compose function 100 times. As with the example tests, there are multiple assertions which check the validity of the string returned by your code

The instruction mentions 100 random tests, but there are way more than 100 tested!

Haskell translation

I think an example would be too much of a spoiler

Quite poorly explained. Please put at least one example.

Mathy kata indeed, good to learn something new.

Whatabout to disallow the text "builtins" in the solution?

this, at least, seems like too low effort
https://www.codewars.com/kata/reviews/66f41701c7df7433a42a90ef/groups/66f9a1dedd10edb549a119bf

I agree, thats brilliant