Deterministic and unambiguous two-dimensional languages over one-letter alphabet
نویسندگان
چکیده
منابع مشابه
Unambiguous Conjunctive Grammars over a One-Letter Alphabet
It is demonstrated that unambiguous conjunctive grammars over a unary alphabet Σ = {a} have non-trivial expressive power, and that their basic properties are undecidable. The key result is that for every base k > 11 and for every one-way real-time cellular automaton operating over the alphabet of base-k digits { d k+9 4 e, . . . , b k+1 2 c } , the language of all strings a with the base-k nota...
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NFA usually requires significantly less states than DFA to recognize the same language. NFAs in one letter input alphabet are more restricted and the gap between NFAs and DFAs decreases, because the power of NFA is in its ability to reach many subsets of its state set. We discuss limitations of DFAs in one letter input alphabet and show that approximately 1/4 of all subsets are unreachable and ...
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ژورنال
عنوان ژورنال: Theoretical Computer Science
سال: 2009
ISSN: 0304-3975
DOI: 10.1016/j.tcs.2008.12.009