Re: Is a contextfree Grammar ambiguous ?

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

          From comp.compilers

Related articles
Is a contextfree Grammar ambiguous ? mmeyer@rhso.de (Martin Meyer) (1998-10-30)
Re: Is a contextfree Grammar ambiguous ? clark@quarry.zk3.dec.com (Chris Clark USG) (1998-11-06)
Re: Is a contextfree Grammar ambiguous ? mickunas@cs.uiuc.edu (1998-11-07)
Re: Is a contextfree Grammar ambiguous ? mickunas@cs.uiuc.edu (1998-11-07)
Re: Is a contextfree Grammar ambiguous ? aycock@csc.uvic.ca (1998-11-07)
Re: Is a contextfree Grammar ambiguous ? dmr@plan9.bell-labs.com (1998-11-07)
Re: Is a contextfree Grammar ambiguous ? cfc@world.std.com (Chris F Clark) (1998-11-07)
Re: Is a contextfree Grammar ambiguous ? cfc@world.std.com (Chris F Clark) (1998-11-12)
Re: Is a contextfree Grammar ambiguous ? jmlake@unity.ncsu.edu (1998-11-15)
| List of all articles for this month |
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


*****************************************************************************
Chris Clark Internet : cfc@world.std.com
Compiler Resources, Inc. CompuServe : 74252,1375
3 Proctor Street voice : (508) 435-5016
Hopkinton, MA 01748 USA fax : (508) 435-4847 (24 hours)
------------------------------------------------------------------------------
Web Site in Progress: Web Site : http://world.std.com/~compres


Post a followup to this message

Return to the comp.compilers page.
Search the comp.compilers archives again.