The State Complexities of Some Basic Operations on Regular Languages
- Sheng Yu, Q. Zhuang, K. Salomaa
- Computer ScienceTheoretical Computer Science
- 28 March 1994
State complexity of basic operations on suffix-free regular languages
- Yo-Sub Han, K. Salomaa
- Computer ScienceTheoretical Computer Science
- 26 August 2007
A sharpening of the Parikh mapping
- A. Mateescu, A. Salomaa, K. Salomaa, Sheng Yu
- MathematicsRAIRO - Theoretical Informatics and Applications
- 1 November 2001
A sharpening of the Parikh map- ping is introduced and an interesting in- terconnection between mirror images of words and inverses of matrices is established.
Decision Problems for Patterns
- Tao Jiang, A. Salomaa, K. Salomaa, Sheng Yu
- Mathematics, Computer ScienceJournal of computer and system sciences (Print)
- 1 February 1995
We settle an open problem, the inclusion problem for pattern languages. This is the first known case where inclusion is undecidable for generative devices having a trivially decidable equivalence…
Deterministic Tree Pushdown Automata and Monadic Tree Rewriting Systems
- K. Salomaa
- Computer ScienceJournal of computer and system sciences (Print)
- 1 December 1988
Pattern languages with and without erasing
- T. Jiang, E. Kinber, A. Salomaa, K. Salomaa, Sheng Yu
- Mathematics
- 1994
The paper deals with the problems related to finding a pattern common to all words in a given set. We restrict our attention to patterns expressible by the use of variables ranging over words. Two…
State Complexity of Basic Operations on Finite Languages
- C. Câmpeanu, K. Culík, K. Salomaa, Sheng Yu
- Computer ScienceWIA
- 17 July 1999
It is shown that the catenation of two finite languages accepted by an m- state and an n-state DFA, respectively, with m > n is accepted by a DFA of (m - n + 3)2n-2 - 1 states in the two-letter alphabet case, and this bound is shown to be reachable.
Operational State Complexity of Prefix-Free Regular Languages
- Yo-Sub Han, K. Salomaa, D. Wood
- Mathematics, Computer ScienceAutomata, Formal Languages, and Related Topics
- 2009
A Formal Study Of Practical Regular Expressions
- C. Câmpeanu, K. Salomaa, Sheng Yu
- Computer ScienceInternational Journal of Foundations of Computer…
- 1 December 2003
It is shown that the languages represented by extended regex are incomparable with context-free languages and a proper subset of context-sensitive languages.
State Complexity of Union and Intersection of Finite Languages
- Yo-Sub Han, K. Salomaa
- Computer ScienceInternational Journal of Foundations of Computer…
- 3 July 2007
The upper bounds based on the structural properties of minimal deterministic finite-state automata for finite languages show that the upper bounds are tight if the authors have a variable sized alphabet that can depend on the size of input DFAs.
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