COMS W3261
Computer Science Theory
Lecture 16: November 14, 2012
Undecidable Problems and Rice's Theorem

Outline

1. Post's Correspondence Problem is Undecidable

2. Rice's Theorem

3. Other Undecidable Problems

4. Big-O Notation

5. The Classes P and NP

6. Practice Problems

  1. Show that it is undecidable whether the language generated by one context-free grammar is contained within the language generated by another context-free grammar.
  2. Show that it is undecidable whether the language accepted by a TM is infinite.
  3. Give an example of a language L such that both L and the complement of L are not recursively enumerable.

7. Reading Assignment



aho@cs.columbia.edu