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From: jwl@garnet.berkeley.edu (James Wilbur Lewis)
Newsgroups: comp.lang.misc
Subject: Re: Complexity of syntax
Message-ID: <1991Jan5.081755.23488@agate.berkeley.edu>
Date: 5 Jan 91 08:17:55 GMT
References: <11883:Jan502:21:0191@kramden.acf.nyu.edu> <1991Jan5.044445.15116@agate.berkeley.edu> <13857:Jan506:12:5891@kramden.acf.nyu.edu>
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In article <13857:Jan506:12:5891@kramden.acf.nyu.edu> brnstnd@kramden.acf.nyu.edu (Dan Bernstein) writes:
-In article <1991Jan5.044445.15116@agate.berkeley.edu> jwl@garnet.berkeley.edu (James Wilbur Lewis) writes:
-> In article <11883:Jan502:21:0191@kramden.acf.nyu.edu> brnstnd@kramden.acf.nyu.edu (Dan Bernstein) writes:
-> -  [ syntax versus semantics ]
-> -> For
-> -> example, is the restriction that you can't declare the same identifier
-> -> twice in the same declaration syntactic or semantic?
-> -Syntax. It has no effect on semantics.
-> Gee, all the C grammars I've seen allow the same identifier to be declared
-> any number of times.
-
-Who said he was referring specifically to C?

No one did, although it was a reasonable thing to infer from the context.
Perhaps the poster who asked the above question can verify that he was 
referring to C.  It doesn't really matter; my challenge still stands.

Choose any language you like, or make one up, subject to the conditions of
the original question: that it allows a large number of identifiers to be 
declared in a single declaration, with the restriction that each identifier 
may appear at most once in that declaration.  I believe that you're wrong to 
refer to that restriction as "syntactic", and am interested in seeing what 
kind of grammar you can write that will generate all the valid declarations 
for that language (and no invalid declarations).  Please show *all* your 
work. :-)

-- Jim Lewis