Date: Mon, 7 Sep 2015 15:13:41 +0000
   From: Taylor R Campbell <xxxxxx@mumble.net>

   Some of the text was lifted verbatim from the MIT Scheme reference
   manual, including most of the paragraph starting `This procedure must
   be used with care...'.  This should be acknowledged.  (It's also not
   clear which procedure `this procedure' refers to.)

Sorry, I missed this line:  `Much of this specification is derived
with thanks from the MIT Scheme specification.'  Might be better to
say `MIT Scheme Reference Manual', not `MIT Scheme specification'.