Re: Is a contextfree Grammar ambiguous ?

Chris F Clark <cfc@world.std.com>
7 Nov 1998 01:28:28 -0500

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From: Chris F Clark <cfc@world.std.com>
Newsgroups: comp.compilers,comp.theory
Date: 7 Nov 1998 01:28:28 -0500
Organization: The World Public Access UNIX, Brookline, MA
Distribution: inet
References: 98-10-172 98-11-037
Keywords: parse, theory

My apologies to all for writing incorrectly:
> The semantic nit is that by definition a context free grammar is
> unambiguous. That is, if your grammar is ambiguous it is not a
> context free grammar.


I mispoke. The original question was worded properly. The definition
of context free grammars does not require that they be unambiguous.
In fact, any grammar defined by [E]BNF with one nonterminal on each
LHS is a context free grammar. I had another reason to look up the
definition of context free grammars and realized my error.


Hope this helps,
-Chris


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