lambda cannot express letrec. Macro-expanding the top-level into a letrec and then showing its semantics would, again, make it harder to follow along with traces of a reduction sequence.
(Also, as I understand it, the jury is still out on whether or not the top-level of a module is the same as a lambda. See Kent's earlier formal comment.) Robby On 3/14/07, AndrevanTonder <[EMAIL PROTECTED]> wrote:
--- This message is a formal comment which was submitted to [EMAIL PROTECTED], following the requirements described at: http://www.r6rs.org/process.html --- 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: -------- Formal semantics of library toplevel is meaningless, unnecessary and clashes with the description in the body of the document. It should be removed. Description: ------------ 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: ----------- 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. _______________________________________________ r6rs-discuss mailing list [email protected] http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
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