[r6rs-discuss] [Formal] Drop formal semantics of library toplevel

[AndrevanTonder]

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This message is a formal comment which was submitted to formal-comment at r6rs.org, following the requirements described at: http://www.r6rs.org/process.html
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Name        : Andre van Tonder
Email       : andre at het.brown.edu
Type        : simplification
Priority    : medium
Component   : formal semantics
Version     : 5.92
Pages       : 71-73
Dependencies: None

Summary:
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Formal semantics of library toplevel is meaningless, unnecessary and clashes 
with the description in the body of the document.  It should be removed.

Description:
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The formal description of the library semantics unnecessarily 
adds significant volume to the formal semantics.  It is also inconsistent
with the informal description of the library semantics and "expansion process"
described in the body of the document.

According to the description in the text, a library residualizes to the 
equivalent of a LETREC* expression.  Therefore

   1) Its semantics can be reduced to that of LAMBDA.
   2) Because of (1), the formal semantics for libraries is redundant
      and should be removed.
   3) Even worse, the formal semantics for libraries is meaningless.
      It purports to give a semantics to DEFINE forms.  However, an
      expanded library contains no DEFINEs, just a LETREC*.

Suggestion:
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Remove the formal semantics of libraries.  It should be sufficient
to include a note that since libraries expand to LETREC*, their semantics can 
be understood in terms of LAMBDA.