Substring & friends

[Gary Brooks <brooks%tilde%TI-CSL.CSNET@CSNET-RELAY.ARPA>]

As stated in the R^3 Report, the documentation for the <start> and <end>
indices for substring & friends is consfused.  The report states that
<start> and <end> must be valid indices (with <start> <= <end>).  This
is certainly not the case if you are taking the substring of an entire
string, where the index for <end> must be one greater than the largest
valid index.  The previous report, RRRS, included a paragraph explaining
that <start> is inclusive and <end> is exclusive, which is clearer
though still inconsistant with the documentation for substring.  This
inconsistency should be rectified.

On the other hand <start> and <end> could be defined to both be
inclusive.  Now, I realize that there are probably too many instances of
substring & friends running around, and that this would be incompatible
with CL's subsequence, but I for one dislike the notion of (exclusive)
indices that may not be (really) valid indices.  Comments?

			-- brooks