Re: Difference letrec & environment binding (again)

[Hans Aberg]

On 10 Nov 2011, at 00:11, Andy Wingo wrote:

> On Thu 04 Aug 2011 10:56, Hans Aberg <address@hidden> writes:
> 
>> I try to understand how Guile transforms 'letrec' (returning to the
>> topic of an earlier post on this list).
> 
> `letrec' is translated to various things, some of which are not Scheme.
> As Ludo notes, see the "Fixing Letrec" paper by Dybvig et al.

My mail somehow got scrambled. Yes, that is the paper I independently found. It 
says that letrec is in R5RS defined, though I could not find the place, as
  (letrec ([x1 e1] ... [xn en]) body)
~>
  (let ([x1 undefined] ... [xn undefined])
    (let ([t1 e1] ... [tn en])
      (set! x1 t1)
      ...
      (set! xn tn))
    body)

Hans