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Re: requiring proper tail recursion

   Date: Tue, 02 Sep 1997 10:13:25 -0500
   From: William D Clinger <will@ccs.neu.edu>

   There is another difficulty with this definition of proper tail
   recursion:  In some implementations, CALL-WITH-CURRENT-CONTINUATION
   changes the representation of a continuation in ways that make it
   occupy additional space.  Furthermore repeated uses of CALL/CC to
   capture the same continuation might create multiple copies.  Both
   kinds of implementation of CALL/CC are forbidden by the following
   definition of proper tail recursion.

But your original message of Mon, 02 Jun 1997 proposed:

  2.  Define proper tail recursion in terms of the asymptotic
      space used by continuations.

Doesn't the term `asymptotic' allow an implementation to consume space
for continuations, so long as those continuations can be collected?

I am a guest and *not* a member of the MIT Artificial Intelligence Lab.
      My actions and comments do not reflect in any way on MIT.