A. Amarilli and M. Jeanmougin, "A proof of the pumping lemma for context-free languages through pushdown automata," CoRR, abs/1207.2819, 2012.Amarilli, A., Jeanmougin, M.: A proof of the pumping lemma for context-free languages through pushdown automata. CoRR, abs/1207.2819 (2012)...
we show that a pumping lemma for a class of languagesCCcan be used to study the computational complexity of the predicate “∈CC” via highly efficient many-one reductions. In this paper, we use extended regular expressions (EXREGs, introduced in Câmpeanu et al...
Proof i) We begin by proving the result concerning the minimal pumping constant. Let us consider a language . By Lemma 3, we have that if and only L is empty, which implies thus as showed in Example 2. This proves that . Now suppose that L is non-empty, and let w be a non-empt...
Steps of a “Pumping Lemma” Proof Nonmechanical elements of a “pumping lemma”-based nonregularity proof Choose x of length at least n. Choose m (often 0 or 2, never 1) Derive the contradiction Some examples: L 1 = {a i | i is a square} ...
The pumping lemma is often used to prove that a particular language is non-regular: aproof by contradiction(of the language's regularity) may consist of exhibiting a word (of the required length) in the language which lacks the property outlined in the pumping lemma. ...
1. Proof of Non-Regularity of LanguagesOne of the most common uses of the Pumping Lemma is in language classes, where it is used to prove the irregularity of a certain language by highlighting that no matter which division of a string in that language is made, the conditions given by the...
We develop a pumping lemma for HORS by using a novel but simple intersection type system for reasoning about reductions of lambda-terms. Our proof is arguably much simpler than the proof of Kartzow and Parys' pumping lemma for collapsible pushdown automata. As an application, we give an ...
A Pumping Lemma for Pushdown Graphs of Any Level We present a pumping lemma for the class of epsilon-contractions of pushdown graphs of level n, for each n. A pumping lemma was proposed by Blumensath, but there is an irrecoverable error in his proof; we present a new proof. Our pumping...
因此，如果可以构建一台机器来读取这种语言，那么一定有一个循环在其中，以保持有限的状态数量。添加这些...
THE EQUIVALENCE BETWEEN 2Gs AND 2Es AND A NEW PROOF TO PUMPING LEMMA 语言,文法,二型表达式,泵作用引理简要介绍了二型表达式的概念,严格证明了上下文无关语言类恰是二型表达式所表达的语言类.然后,使用二型表达式对关于上下文无关语言的泵作用引理给出了一个新的证明VIP天津大学学报(英文版)...