Not exactly. I had to use SelectMany (flatmap) in my .csx solution, but the core of the solution is the join (or the for-if in the python list comprehension sol

Not exactly. I had to use SelectMany (flatmap) in my .csx solution, but the core of the solution is the join (or the for-if in the python list comprehension solution and the if-guard over the list monad in the F#/Haskell solutions)