My Solution! Haha!

kudos if this was on purpose, else i recommend checking out regexp :)

Yeap))

yeah this kata needs random tests

I usually manage 4kyu challenges in 30 mins or less, but this took me 6h40mins! I'm not inexperienced in code golfing.
It was an amazing challenge and I enjoyed every minute, even if I slowly lost my sanity.

I think it should be ranked 2 or 3 kyu

thinking that comp was about calculating the nth number in u

Description says:
"Given n (integer > 2) write the function comp(n) returning the number of times where a term of u is less than its predecessor up to and including u[n]."

comp and lengthSupUK are terrible function names. I got stuck for 10 minutes thinking that comp was about calculating the nth number in u. Please change them to something more intuitive

Truncating results doesn't add anything but confusion to the kata. Should I truncate intermediate results? If not I can't use recursive code. Just don't, and polish up the tests.

It's also practically a double of the Evaluate Mathematical Expression - needed one more line of code for the functions. (Oh, and two minimal adjustments to the tokeniser.)

Still, if you do it right, it adds functions to said kata. It's a lot more interesting to build a parser (again, and again, and again) than to find the umpteenth cheat (again, and again, and again) that hasn't been disabled.

What?

Add more example cases.