Context-free grammars for permutations and increasing trees
نویسندگان
چکیده
منابع مشابه
Increasing trees and alternating permutations
In this article we consider some increasing trees, the number of which is equal to the number of alternating (updown) permutations, that is, permutations of the form σ(1) < σ(2) > σ(3) < ... . It turns out that there are several such classes of increasing trees, each of which is interesting in itself. Special attention is paid to the study of various statistics on these trees, connected with th...
متن کاملEmpirical Analysis of Context Free Grammars and Parse Trees
This research explores the impact of Context Free Grammars (CFG) and Parse Trees for construction of a Telugu Language Sentences. Based on the CFG here we derived the derivations for the respective strings. Later we constructed the Parser Trees for the above said strings. Finally we analysed whether the string is ambiguous or unambiguous. Here for analysis we considered the Large Scale Open Sou...
متن کاملDependency Grammars and Context-Free Grammars
The question arises from time to time what the relation is between dependency grammars (DG’s) and phrase-structure grammars. A classic paper by Gaifman [1] would appear to have laid the issue to rest, by proving that dependency grammars are a special case of context-free grammars (CFG’s). Gaifman proves that dependency grammars are equivalent to a proper subset of phrasestructure grammars, thos...
متن کاملPregroup Grammars and Context-free Grammars
Pregroup grammars were introduced by Lambek [20] as a new formalism of type-logical grammars. They are weakly equivalent to context-free grammars [8]. The proof in one direction uses the fact that context-free languages are closed under homomorphism and inverse homomorphism. Here we present a direct construction of a context-free grammar and a push-down automaton, equivalent to a given pregroup...
متن کاملModularized Context-Free Grammars
Given two context-free grammars (CFGs), G 1 and G 2 , the language generated by the union of the grammars is not the union of the languages generated by each grammar: L(G 1 G 2) 6 = L(G 1) L(G 2). In order to account for mod-ularity of grammars, another way of deening the meaning of grammars is needed. This paper adapts results from the semantics of logic programming languages to CFGs. We discu...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Advances in Applied Mathematics
سال: 2017
ISSN: 0196-8858
DOI: 10.1016/j.aam.2016.07.003