negative index for the sequence

["Scott E. Fahlman" <Fahlman@C.CS.CMU.EDU>]

I find the use of negative indices to mean "count backward from the end
of the sequence" is very confusing, especially in the Common Lisp
sequence functions, may of which already have a :FROM-END option and
other complexities.  This wouldn't be so bad in SUBSEQ alone, but then
it would make that function different from all the others in how it
handles indices.  Maybe this convention works well in TAO, but I don't
think it would work well in Common Lisp.

-- Scott