Questions on F#'s loop and cont
cont is continuing the computation process.

The printListRevTR function, in the process of execution, builds up a "chain" of cont functions. The very first (or last, depending on how you count) such function is the one that prints "Done!". After that, each next cont prints the current number and then calls the previous cont.

As printListRevTR goes through the list, it builds up a chain of conts, by creating each next function that calls the previous one. This chain could be visualized like this:



After the list has been exhausted, the very last iteration calls the very last (or first, depending on how you count) function in that chain, which calls the next one, which calls the next one, and so on, until the final "Done!" function is called.

As for loop - that's not a keyword, just a name that Juliet has chosen for her function.