> Why start = length is an error?  Vectors and strings allow it.  R7RS
only says start <= end and end <= length.

I find (vector-copy '#(0 1 2) 3) to be strange as I would expect that
the 3rd element (which doesn't exist) to be in that list, as `start` is
inclusive.

However, if the R7RS allows it, I will align the SRFI with the R7RS.

-- Peter McGoron