Re: LALR(1)- but not LR(1)-conflict

adam@index.ping.dk (Adam Dickmeiss)
Sat, 18 Feb 1995 16:27:00 GMT

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Re: LALR(1)- but not LR(1)-conflict adam@index.ping.dk (1995-02-02)
Re: LALR(1)- but not LR(1)-conflict salomon@silver.cs.umanitoba.ca (1995-02-03)
Re: LALR(1)- but not LR(1)-conflict Robert.Corbett@Eng.Sun.COM (1995-02-04)
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Re: LALR(1)- but not LR(1)-conflict ludemann@netcom.com (1995-02-12)
Re: LALR(1)- but not LR(1)-conflict adam@index.ping.dk (1995-02-18)
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Newsgroups: comp.compilers
From: adam@index.ping.dk (Adam Dickmeiss)
Keywords: parse, LR(1), LALR
Organization: Index Data, Denmark.
References: 95-02-105
Date: Sat, 18 Feb 1995 16:27:00 GMT

About the first grammar presented by Peter Ludemann:

The grammar presented is not even LR(1). This is due to the fact that
it only contains shift/reduce conflicts. If a grammar is LR(1) but
not LALR then there have to be at least one reduce/reduce conflict.

I asked myself, is it ambiguous or is it LR(2) or higher. I tried
to search for two leftmost derivations for the same sentence but
I cannot find one.

I believe that the grammar is really LR(2), but I cannot prove that.

-- Adam
--

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