subseq and consing

[Richard M. Stallman <RMS at MIT-AI>]

Even if SUBSEQ itself conses,
if you offer compiler optimizations which take expressions
where sequence functions are applied to calls to subseq
and turn them into calls to other internal functions which
take extra args and avoid consing, this is good enough
in efficiency and provides the same simplicity in user interface.

While on the subject, how about eliminating all the functions
to set this or that from the language description
(except a few for Maclisp compatibility) and making SETF
the only way to set anything?
The only use for the setting-functions themselves, as opposed
to SETF, is to pass to a functional--they are more efficient perhaps
than a user-written function that just uses SETF.  However, such
user-written functions that only use SETF can be made to expand
into the internal functions which exist to do the dirty work.
This change would greatly simplify the language.