Research output: Contribution to journal › Article › peer-review
Expressive power of LL(k) boolean grammars. / Okhotin, Alexander.
In: Theoretical Computer Science, Vol. 412, No. 39, 09.09.2011, p. 5132-5155.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Expressive power of LL(k) boolean grammars
AU - Okhotin, Alexander
PY - 2011/9/9
Y1 - 2011/9/9
N2 - The paper studies the family of Boolean LL languages, generated by Boolean grammars and usable with the recursive descent parsing. It is demonstrated that over a one-letter alphabet, these languages are always regular, while Boolean LL subsets of Σ*a* obey a certain periodicity property, which, in particular, makes the language anb2n|n0 non-representable. It is also shown that linear conjunctive LL grammars cannot generate any language of the form L·a,b, with L non-regular, and that no languages of the form L·c*, with non-regular L, can be generated by any linear Boolean LL grammars. These results are used to establish a detailed hierarchy and closure properties of these and related families of formal languages.
AB - The paper studies the family of Boolean LL languages, generated by Boolean grammars and usable with the recursive descent parsing. It is demonstrated that over a one-letter alphabet, these languages are always regular, while Boolean LL subsets of Σ*a* obey a certain periodicity property, which, in particular, makes the language anb2n|n0 non-representable. It is also shown that linear conjunctive LL grammars cannot generate any language of the form L·a,b, with L non-regular, and that no languages of the form L·c*, with non-regular L, can be generated by any linear Boolean LL grammars. These results are used to establish a detailed hierarchy and closure properties of these and related families of formal languages.
KW - Boolean grammars
KW - Conjunctive grammars
KW - Context-free grammars
KW - Language equations
KW - LL grammars
KW - Parsing
KW - Recursive descent
UR - http://www.scopus.com/inward/record.url?scp=80051664073&partnerID=8YFLogxK
U2 - 10.1016/j.tcs.2011.05.013
DO - 10.1016/j.tcs.2011.05.013
M3 - Article
AN - SCOPUS:80051664073
VL - 412
SP - 5132
EP - 5155
JO - Theoretical Computer Science
JF - Theoretical Computer Science
SN - 0304-3975
IS - 39
ER -
ID: 41140892