On some context free languages that are not deterministic ETOL languages
نویسندگان
چکیده
منابع مشابه
Tape Bounds for Some Subclasses of Deterministic Context-Free Languages
There are several interesting observations to be made concerning the tape complexity of context-free languages. An early result given by Lewis et al. (1965) is that every context-free language can be recognized by an off-line deterministic Turing machine of O((log n) 2) tape complexity. This is still the best result known. Sudborough (1975) shows that if all linear context-free languages can be...
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Recently considerable interest has been shown in questions concerning the complexity of the membership problem for various types of L systems3 In van Leeuwen (1975a) it is shown that there is an E T O L system G such that the set L(G) is ~/ '~-complete . Opatrn3~ and Culik (1975) showed that EOL membership could be determined by a D T I M E (n 4) algorithm, and Sudborough (1976) gave a DSPACE((...
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Let C = {a,, a2, . . . . a,} be an alphabet and let LcZ* be the commutative image of FP* where F and P are finite subsets of Z*. If, for any permutation c of { 1,2, . . . . n}, L n a&) a%, is context-free, then L is context-free. This theorem provides a solution to the Fliess conjecture in a restricted case. If the result could be extended to finite unions of the FP* above, the Fliess conjectur...
متن کاملOn strongly context-free languages
Starting from the question (inspired by the so-called computing by carving, from the DNA-based computing area) \which is easier to generate, a language or its complement?", we brie y investigate the context-free languages whose complements are also context-free. We call them strongly context-free languages. After examining the closure properties of the family of strongly context-free languages,...
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ژورنال
عنوان ژورنال: RAIRO. Informatique théorique
سال: 1977
ISSN: 0399-0540
DOI: 10.1051/ita/1977110402731