Tail recursion, etc.

[Kent Pitman <kmp@harlequin.com>]

   From: ramsdell@linus.mitre.org (John D. Ramsdell)
   Date: 10 Sep 1997 13:51:44 -0400

   "Guillermo J. Rozas" <gjr@martigny.ai.mit.edu> writes:

   > I don't like the term "tail expression".

   I don't have an alternative at this time so I'll continue using it.

Terminal expression?  Result expression?

   > One thing that the proposed formalizations do not seem to embody is
   > that the notions of "tail call", "tail expression", "reduction",
   > etc. are not absolute, but relative to some starting point.

Then add weasel words "blah-blah is called a tail expression of that expression".
Gives you an excuse to use some application of transitivity to show what the full
set of tail expressions  for a definition are.

   Yes.  I agree.  This is one feature that was present in the
   formalization of tail combinations I presented for the lambda calculus
   using tail combination contexts that was lost when I tried to apply
   that formalism to Scheme.  I close with an incomplete version of the
   text that attempts to fix this problem.