I'll ungolf it so we can actually read what it's doing, just a sec.

Ungolfed version: tio.run/…

What is # (a,b)?

splitAt (length list/2) list returns the type ([.t], [.t]), which is equated to (a, b)

So it sets a to the first split part, and b to the second

I think it's like the let keyword in haskell?

Got it

Now, what are the two branches of the if?

(if(a > []) [[list]:[x ++ y \\ y <- fn b & x <- fn a ++ fn a ++ fn a]] []) = [[list]:[x ++ y \\ y <- fn b & x <- fn a ++ fn a ++ fn a]] when a is not the empty list, otherwise it's the empty list

it's like a C-style ternary, if(cond) true false

++ is list concatenation, and [head:tail] is cons - I don't know if cons in haskell needs the square brackets, but in Clean [1:[2,3]] is [1, 2, 3]

Right now I have this …

Ah. Clean list comprehensions are synchronous over all sources prefixed with &, examples:

tio.run/##S85JTcz7/z83P6U0J1UhNzEzjysztyC/…

tio.run/##S85JTcz7/z83P6U0J1UhNzEzjysztyC/…

Without golfing, I have this

If a==[], does u==[]?

if a==[], length u < 2

because [1] gets split into ([],[1])

Is u ever []?

Nope

110 Can still be shorter