Level 4.1 solution not recognized

[jonashw]

From what I can tell, I met the goal on level 4.1 but the game does not recognize my solution.
My solution: [map(x2), map(+1), filter even, map(-1)]. See attached screenshot:

[jonashw]

It's worth noting that the solution above is not the optimal solution (there is a 2-function solution contained within that solution) but it still meets the goal.

[sharkdp]

After map (x2) and map (+1), every number is odd. Then, you apply filter even, which means you get the empty list. So this is not a solution (the 2-function solution that you mention, is a solution).

Unfortunately, the place holder for the empty list is not shown. I'll look into this.

[jonashw]

Ah, that makes sense.

[sharkdp]

Fixed! Thanks for reporting this.