Is that, plus an understanding of the non-in-place merge sort algorithm not enough to make a merge sort? I mean, you need to pick what basic understanding you assume in any explanation.
EDIT: To be clear, I think it's an explanation of "You know how to merge sort, but not how to do it in place? Here's how!"
EDIT: To be clear, I think it's an explanation of "You know how to merge sort, but not how to do it in place? Here's how!"