CSCI 8610	     Topics in Theoretical Computer Science       Fall 2006

		       	        Homework set #6

		     Due by 5:00 PM on Thursday, November 16 

These problems are from Chapter 7 of the notes by Shallit.

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1. (40 points) Prove these CSL closure properties without assuming or using the
   closure under complementation.
   
2. (20 points)

5. (20 points) Held over from HW set 5.

9. (20 points)

12. (20 points)