Sample Midterm questions (Cmps 132, Winter 07, Warmuth) 1. Given a TM. figure out what language it accepts or function it computes. 2. Construct a TM for solving a simple problem. 3. Give the Church-Turing thesis. Is your laptop equivalent to a TM? 4. Defs of universal and completeness. 5. What are the inputs to a universal TM? What does it do? 6. Defs of T. acceptable and T. decidable. 7. Closure properties of T. a. and T. d. languages (Thms 10.1 to 10.6) 8. Equivalence between T. a. and T. enumerable. 9. Equivalence between T. d. and T. enumerable in lexicographic order 10. Diagonalization argument for showing that for example the set of languages over a finite alphabet is uncountably infinite. 11. Show that the countable union of countable sets is countable. 12. Use a counting argument to show that there are languages that are not T. a. 13. Def. of SA and NSA 14. Use the fact that NSA is not T.a. to show that SA is not T.d. 15. Given an (unrestricted) grammar, show what language it accepts. 16. Given a description of a language, construct an unrestricted grammar that generates it. 17. What is the relationship between the languages generated by unrestricted grammars and the T. a. languages? 18. Show that context sensitive languages are decidable. 19. Know the definition of the Halting Problem and the language H. Know what it means that the Halting Problem is undecidable. 20. Give a proof that the Halting Problem is undecidable. 21. Be familiar with diagonalization arguments! 22. Show that a problem is unsolvable by reducing a known unsolvable problem to it. 23. Know the statement of Rice's theorem and how to apply it