Results 91 to 100 of about 283,476 (338)

Structural equivalence of context-free grammars

8th Annual Symposium on Switching and Automata Theory (SWAT 1967), 1967
AbstractTwo context-free grammars are defined as being structurally-equivalent if they generate the same sentences and assign similar parse trees (differing only in the labelling of the nodes) to each. It is argued that this type of equivalence is more significant than weak equivalence, which requires only that the same sentences be generated.
Marvin C. Paull, Stephen H. Unger
openaire   +3 more sources

Selection of DNA Aptamers Against Parathyroid Hormone for Electrochemical Impedimetric Biosensor System Development

Biotechnology and Applied Biochemistry, EarlyView.
ABSTRACT This work presents the pioneering development of an aptamer‐based electrochemical biosensor for real‐time monitoring of parathyroid hormone (PTH) levels, with a focus on intraoperative assessment during parathyroid surgery. It introduces, for the first time, the selection and characterization of aptamers targeting distinct segments of the PTH ...
Reza Didarian, Saharnaz Bargh, Almina Gülerman, Veli Cengiz Özalp, Özcan Erel, Nimet Yildirim‐Tirgil   +5 more
wiley   +1 more source

LexGram - a practical categorial grammar formalism - [PDF]

Proc.CLNLP95, Edinburgh, 1995
We present the LexGram system, an amalgam of (Lambek) categorial grammar and Head Driven Phrase Structure Grammar (HPSG), and show that the grammar formalism it implements is a well-structured and useful tool for actual grammar development.
arxiv  

Macros for context-free grammars [PDF]

Proceedings of the 10th international ACM SIGPLAN conference on Principles and practice of declarative programming, 2008
Current parser generators are based on context-free grammars. Because such grammars lack abstraction facilities, the resulting specifications are often not easy to read. Fischer's macro grammars extend context-free grammars with macro-like productions thus providing the equivalent of procedural abstraction. However, their use is hampered by the lack of
Matthias Neubauer, Peter Thiemann
openaire   +2 more sources

Basic Classes of Grammars with Prohibition [PDF]

arXiv, 2013
A practical tool for natural language modeling and development of human-machine interaction is developed in the context of formal grammars and languages. A new type of formal grammars, called grammars with prohibition, is introduced. Grammars with prohibition provide more powerful tools for natural language generation and better describe processes of ...
arxiv  

Ability grouping in primary physical education in England: Moving beyond binary discourses and practices

British Educational Research Journal, EarlyView.
Abstract This study recognised that there is currently limited understanding of the extent and nature of ability grouping practices in subject areas other than mathematics and English in primary schools. Using survey methods, this research sought to generate data of sufficient scale to extend understanding of the use of ability grouping practices in ...
Shaun D. Wilkinson, Dawn Penney
wiley   +1 more source

Van Wijngaarden grammars, metamorphism and K-ary malwares [PDF]

arXiv, 2010
Grammars are used to describe sentences structure, thanks to some sets of rules, which depends on the grammar type. A classification of grammars has been made by Noam Chomsky, which led to four well-known types. Yet, there are other types of grammars, which do not exactly fit in Chomsky's classification, such as the two-level grammars.
arxiv  

Nonterminal Separating Macro Grammars [PDF]

, 1987
We extend the concept of nonterminal separating (or NTS) context-free grammar to nonterminal separating $m$-macro grammar where the mode of derivation $m$ is equal to "unrestricted". "outside-in' or "inside-out".
Hogendorp, Jan Anne
core   +3 more sources

Restricted Global Grammar Constraints [PDF]

arXiv, 2009
We investigate the global GRAMMAR constraint over restricted classes of context free grammars like deterministic and unambiguous context-free grammars. We show that detecting disentailment for the GRAMMAR constraint in these cases is as hard as parsing an unrestricted context free grammar.We also consider the class of linear grammars and give a ...
arxiv  

Learning of Structurally Unambiguous Probabilistic Grammars [PDF]

arXiv, 2020
The problem of identifying a probabilistic context free grammar has two aspects: the first is determining the grammar's topology (the rules of the grammar) and the second is estimating probabilistic weights for each rule. Given the hardness results for learning context-free grammars in general, and probabilistic grammars in particular, most of the ...
arxiv