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derived expression types



R4RS looks great!  Thanks all.

Let me suggest that some small changes be made in R5RS.  In section
7.3, titled "Derived expression types", please add text that makes it
clear the section contains transformations that rewrites correct
expressions into correct expressions, and that it does to precisely
define all derived expressions.  For example (COND) is not legal even
though the rules might encourage one to think it is legal.  Also, there
is a missing rule for DO:

	(do ((<variable> <init> <step>) ...)
	    (<test>)
          <command> ...)

		==>

	(letrec ((<loop> (lambda (<variable> ...)
			   (or <test>
			       (begin 
				 <command> ... 
				 (<loop> <step> ...))))))
	  (<loop> <init> ...))

John

PS. Some people on comp.lang.scheme seem quite confused by this section.