A pumping lemma for DLI-languages
A pumping lemma for DLI-languages
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DOI:
10.1016/s0012-365x(02)00265-0
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发表时间:
2002-12-06
影响因子:
0.8
通讯作者:
K치szonyi, L
中科院分区:
文献类型:
--
作者:
K치szonyi, L
Stratified linear sets play a central role in the theory of bounded context-free languages, developed by Ginsburg (The Mathematical Theory of Context-Free Languages, McGraw-Hill, New York, 1966). The "Flip-Flop Lemma," (Pure Math. Appl. Ser. A 6(2) (1995) 203), states, that the vector-set{(e(0),...,e(m-1)) is an element ofN(m) \delta(0)e(0) +(...)+ delta(m-1)e(m-1) not equal 0}where delta(i)is an element of {-1,0, 1}, for i = 0,...,m - 1, and N denotes the set of non-negative integers, is a stratified semilinear set, i.e., a finite union of stratified linear sets. In this paper, we generalize the statement of the lemma giving a necessary and sufficient condition for a DLI-set (i.e., for a vector-set Defined by Linear Inequalities) to be stratified semilinear. (C) 2002 Elsevier Science B.V. All rights reserved.