When using F# to solve puzzles, there are some seemingly normal functions that aren’t allowed. For example, it’s perfectly valid to use
Array.unfold with the current version of mono/F#, but if I use it on a problem here I get:
error FS0039: The value, constructor, namespace or type 'unfold' is not defined
Is this a result of the version of F# being used by the system being out of date, a quirk in the system, or am I doing something wrong?