Polynomial Size Test Sets For Context-Free Languages
β Scribed by J. Karhumaki; W. Plandowski; W. Rytter
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 648 KB
- Volume
- 50
- Category
- Article
- ISSN
- 0022-0000
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β¦ Synopsis
We prove that each context-free language possesses a test set of size (O\left(m^{6}\right)), where (m) is the number of productions in a grammar-producing the language. A context-free grammar generating the test set can be found in polynomial time by a sequential algorithm. It improves the doubly exponential upper bound from [2] and single exponential one from J. KarhumΓ€ki, W. Rytter, and S. Jarominek (Theoret. Comput. Sci. (116(1993), 305-316)). On the other hand, we show that the lower bound for the problem is (\Omega\left(\mathrm{m}^{3}\right)) and that the lower bound for the size of a test set for a language defined over (n)-letter alphabet is (\Omega\left(n^{3}\right)). c. 1995 Academic Press, Inc.
π SIMILAR VOLUMES
Let A be a finite, totally ordered alphabet, and let P be the lexicographic ordering on A\*. Let X be a subset of A\*. The language of minimal words of X is the subset of X composed of the lexicographically minimal word of X for each length: The aim of this paper is to prove that if L is a context-