Is this grammar LL(1) ?

sky4walk@gmx.de
17 Sep 2005 13:47:52 -0400

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Is this grammar LL(1) ? sky4walk@gmx.de (2005-09-17)
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From: sky4walk@gmx.de
Newsgroups: comp.compilers
Date: 17 Sep 2005 13:47:52 -0400
Organization: http://groups.google.com
Keywords: LL(1), question
Posted-Date: 17 Sep 2005 13:47:52 EDT

Hi,
i've a question about this grammar


E->'a',F,A,F,'b'.
F->'c',F | epsilon.
A->'d',A_1.
A_1->'d',A_1 | epsilon.


is this grammar LL(1)?


my first and follow list


First(E) = {a}
First(F) = {c,epsilon}
First(A) = {d}
First(A_1) = {d,epsilon}


Follow(E) = {}
Follow(F) = {d,b}
Follow(A) = {c,d,b}
Follow(A_1) = {c,d,b}


sp I see, that in Follow(A_1) and First(A_1) is a problem because of
same terminal 'd'.


So my question is:


1) is my follow list correct?
2) when 1) is true, why isn't my grammar LL(1), it isn't leftrecursivea
nd how can I change this one?


Thanks
André Betz
andrebetz.de

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