I searched the internet and here for the answer and found very little that was convincing. Often, an entire algorithm in VBA or other language was given.
Here is my answer; remember, formula; not a VBA subroutine.
For two number ranges m-n and x-y (i.e., m through n and x through y)
Where m, n, x and y could be cell addresses or whatever gives the desired values defining the number ranges.