[phoyd]

Do I miss something, or does the quick sort example fail to handle the case where the value of "fst" is present more than once in the list?

[colonwqbang]

If only there was some way to formally verify that an algorithm is correctly implemented

[rigille]

Thanks for pointing that out! It's now fixed.

[NieDzejkob]

How hard would it be to prove correctness of this quicksort in an example?