F&O comments on subsequence function

A couple comments on the subsequence function:

1. It does not say what the processor should do if $startingLoc is
either negative/zero or greater than the number of items in the
$sourceSeq.  I assume that if it's zero it starts at the beginning, and
if it's larger than the number of items it returns the empty sequence.
Or should it raise an error?

2. The 3rd paragraph ends with "...includes items to the end of $length.
"  I think that should say "includes items to the end of _the sequence_.
"

Thanks,
Priscilla