1 / 31

Erik Jonsson School of Engineering and Computer Science

Erik Jonsson School of Engineering and Computer Science. CS 4384 – 001. Automata Theory. http://www.utdallas.edu/~pervin. Tues day : Section 2.9 Look at Ullman’s Lecture 7. Thursday 1-30-14. FEARLESS Engineering. Rui Li rxl122350@utdallas.edu ECSS4.215 MW 9-11.

valora
Download Presentation

Erik Jonsson School of Engineering and Computer Science

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Erik Jonsson School of Engineering and Computer Science CS 4384– 001 Automata Theory http://www.utdallas.edu/~pervin Tuesday: Section 2.9 Look at Ullman’s Lecture 7 Thursday1-30-14 FEARLESS Engineering

  2. Rui Li • rxl122350@utdallas.edu • ECSS4.215 • MW 9-11 Teaching Assistant

  3. Theorem: If L = L(N) for a NFA N, then L = L(D) for a DFA D. Linz P.61

  4. Union • Concatenation • Kleene Star Regular Expressions

  5. Du method P. 18

  6. Du, Example 1.24, P. 18 & Kozen, Example 9.1, P. 51

  7. Many other answers are possible!

  8. Many other answers are possible!

  9. Many other answers are possible!

  10. Decision Problems Martin, P. 148 (1st Ed.)

  11. PUMPING LEMMA M&S P. 68 Theorem 2.9.1

  12. Proof: If A is regular it has a DFA with a finite number, n, of states. Let p = n. Then for any string s in A of length at least p, suppose the decomposition s = xyz satisfies the conditions.

  13. Examples 1-5 from M&S: Classic Examples

  14. If L is regular then so is its complement!

  15. The intersection with a*b* is necessary because the complement contains all strings with a and b out of order!

  16. If the problem was n > m, then choose s = a^{p+1}b^p which is just at the edge of being in L. Then pump DOWN (i=0) since y must consist of a’s.

  17. Extended Pumping Lemma Essentially the same proof!

More Related