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Ambiguity in omega context free languages

Olivier Finkel
2003 Theoretical Computer Science  
We extend the well-known notions of ambiguity and of degrees of ambiguity of ÿnitary context free languages to the case of omega context free languages (!  ...  We investigate ÿrst properties of the subclasses of omega context free languages we get in that way, giving many examples and studying topological properties of !-CFL of a given degree of ambiguity.  ...  free languages.  ... 
doi:10.1016/s0304-3975(02)00584-4 fatcat:zohu57u5t5dzrh6yjhpiqdf2pe

Topology and Ambiguity in Omega Context Free Languages [article]

Olivier Finkel
2008 arXiv   pre-print
We study the links between the topological complexity of an omega context free language and its degree of ambiguity.  ...  On the other side we show that methods used in the study of omega context free languages can also be applied to study the notion of ambiguity in infinitary rational relations accepted by B\"uchi 2-tape  ...  V 1 and V 2 are deterministic context free, hence they are non ambiguous context free languages. But their union V is an inherently ambiguous context free language [Mau69] .  ... 
arXiv:0801.0533v1 fatcat:upiqvt2lavebtfbhsu24vrxney

Topology and ambiguity in ω-context free languages

Olivier Finkel, Pierre Simonnet
2003 Bulletin of the Belgian Mathematical Society Simon Stevin  
We study the links between the topological complexity of an ω-context free language and its degree of ambiguity.  ...  On the other side we show that methods used in the study of ω-context free languages can also be applied to study the notion of ambiguity in infinitary rational relations accepted by Büchi 2-tape automata  ...  V 1 and V 2 are deterministic context free, hence they are non ambiguous context free languages. But their union V is an inherently ambiguous context free language [Mau69] .  ... 
doi:10.36045/bbms/1074791327 fatcat:abolobmpqjahtmimcaloiiv2o4

Characterization of Context-Free Languages with Polynomially Bounded Ambiguity [chapter]

Klaus Wich
2001 Lecture Notes in Computer Science  
doi:10.1007/3-540-44683-4_61 fatcat:lnigyr4qjfbzzok66d6walchdq

Optimal Ambiguity Packing in Context-Free Parsers with Interleaved Unification [chapter]

Alon Lavie, Carolyn Penstein Rosé
2004 Text, Speech and Language Technology  
Ambiguity packing is a well known technique for enhancing the efficiency of context-free parsers.  ...  However, in the case of unification-augmented context-free parsers where parsing is interleaved with feature unification, the propagation of feature structures imposes difficulties on the ability of the  ...  Ambiguity Packing in Context Free Parsing Ambiguity Packing Many grammars developed for parsing natural language are highly ambiguous.  ... 
doi:10.1007/1-4020-2295-6_15 fatcat:nftm2urignfunb64ubbnaffqzq

Sublogarithmic ambiguity

Klaus Wich
2005 Theoretical Computer Science  
The second one states that any ambiguity function of a cycle-free context-free grammar is an inherent ambiguity function of some context-free language. → . In this case X is called the root of .  ...  Context-free grammars and languages with infinite ambiguity can be distinguished by the growth rate of their ambiguity with respect to the length of the words.  ...  Ambiguous context-free languages are also called inherently ambiguous. The existence of ambiguous context-free languages is shown in [16, 17] .  ... 
doi:10.1016/j.tcs.2005.07.024 fatcat:lvbrv4ak45dfboxmpji4tt6fye

A note on ambiguity in context-free grammars

Tom Altman, George Logothetis
1990 Information Processing Letters  
Context-free grammars (CFGs) and the languages they generate, the context-free languages (CFLs), are useful in defining the syntax of programming languages, formalizing the notion of parsing, and numerous  ...  Introduction We show that ambiguity in context-free grammars can be decomposed into union-ambiguity and concatenation-ambiguity.  ... 
doi:10.1016/0020-0190(90)90058-6 fatcat:jzysva43snfvzcsirjzuk3t4u4

Ambiguity Detection Methods in Context Free Grammar

Sundus Shaukat, Kashif Ayyub, Wasif Nisar, Mudassar Raza, Tariq Umer
2014 Research Journal of Applied Sciences Engineering and Technology  
In parser generation and in language design, ambiguity in context free grammar, is a frequent problem as well as in application where it is used for the representation of physical structure.  ...  Problem arising in CFG (Context Free Grammar) due to ambiguity can be trace to 1962. Even now there is no general method or procedure introduced to detect ambiguity in CFG.  ...  In 2004, Wich (2005) wrote thesis on ambiguity functions of context free grammars and languages. In which different basic definitions are defined relating context free grammar.  ... 
doi:10.19026/rjaset.7.847 fatcat:mzus5de6qbbgpb4rkv3qu63cwi

Sublinear Ambiguity [chapter]

Klaus Wich
2000 Lecture Notes in Computer Science  
In this paper first examples of (linear) context-free languages with nonconstant sublinear ambiguity are presented.  ...  Until now there have only been examples of context-free languages with inherent ambiguity 2 Θ(n) and Θ(n d ) for each d ∈ N0.  ...  In [5] and [6] the ambiguity function has been introduced as a new tool for examining the ambiguity of cycle-free context-free grammars.  ... 
doi:10.1007/3-540-44612-5_64 fatcat:j5n5ztrpvrdv7dqvflvace75iq

Complexity in left-associative grammar

Roland Hausser
1992 Theoretical Computer Science  
Complexity in lqjt-associatiw grammar 295 languages" and all context-free languages with nonrecursive ambiguities.  ...  As a case in point consider the nondeterministic context-free language WWR, defined as follows. Definition 7.1 (Nondeterministic context-free language WWR).  ... 
doi:10.1016/0304-3975(92)90253-c fatcat:stywnpghwrbsjlwr7o2pi4rjti

Inherent ambiguity of minimal linear grammars

Maurice Gross
1964 Information and Control  
We give an example of minimal linear language, all of whose minimal linear grammars are ambiguous; this language is not ambiguous in the class of linear context-free languages.  ...  Parikh has shown that there are context-free languages which are inherently ambiguous; he gave an example of context-free language (in fact linear), all of whose context-free grammars are ambiguous.  ...  Aeeording to Chomsky and Seh~tzenberger, a minimal linear language is generated by a context-free grammar of the particular form: {S---~f~Sgi : 1 <-i < -N } S ---~ c Our example is the language L -= {a  ... 
doi:10.1016/s0019-9958(64)90422-x fatcat:xgbgidzxpfhqdoy46mluym7eri

Page 831 of Mathematical Reviews Vol. 43, Issue 3 [page]

1972 Mathematical Reviews  
can detect all four types of errors in context-free languages.  ...  Moreover, an example of an inherently ambiguous context-free language is given for which the corresponding semilinear set is (1, 2)- ambiguous, showing that ambiguity can be caused by the requirement that  ... 

On ambiguity in E0L systems

A. Ehrenfeucht, G. Rozenberg
1980 Theoretical Computer Science  
It is demonstrated that the degree of ambiguity of a context free language K in the class of EOL systems is not larger than the degree of ambiguity of K in the class of context free grammars.  ...  Using those results several conjectures concerning ambiguity of EOL languages are disproved.  ...  That is, we show that the EOL-ambiguity of a context free language cannot be larger than its context free ambiguity.  ... 
doi:10.1016/0304-3975(80)90025-0 fatcat:kdns7ocztzaofjy7uedi7bo7dq

Page 1246 of Mathematical Reviews Vol. , Issue 82c [page]

1982 Mathematical Reviews  
In other words, what are the trade-offs of CF-ambiguity and EOL-ambiguity of context-free languages?  ...  One particular area of concern was: How is the ambiguity (unambiguity) of a context-free language K with respect to context-free grammars affected when EOL systems are allowed in the generation of K?  ... 

Page 504 of Mathematical Reviews Vol. 35, Issue 2 [page]

1968 Mathematical Reviews  
machine which maps an arbitrarily given context-free language nontrivially into a second arbitrarily given context-free language, and (3) whether an arbitrary context-free grammar is ambiguous.  ...  Chapter I introduces the basic notions such as context-free grammar, context-free language, generation tree, and ambiguity, and presents some elementary facts about them.  ... 
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