COS 550 F10 HW #6 DUE Friday 12/17/10
Please e-mail a PDF version of your HW to me by Midnight Friday 12/17/10

Problem 1 - see below,   30 points
p.240 Problem  1,        30 points
p.258 Problem  2(a)-(d), 10 points
p.265 Problem  2,        10 points
p.265 Problem  6(a),     10 points
ASSOC. PROBLEM below,    10 points
********** Problem Notes *********,
Problem 1

You should write a NDFSA simulator. You may use any reasonable language 
and any reasonable way of entering a NDFSA into the simulator. It should 
have the ability to read an NDFSA description from a file. It should work 
correctly if the NDFSA is actually a FSA. As usual, I expect to see 
comments and good code.

p. 240 Problem 1

As you might expect, give a solution and then run some sample cases on 
your FSA simulator for all problems except 1 (f). For 1 (f) you can give a 
solution using any finite number of states, and you can describe the 
states and not give the graph if you have too many states. For the other 
cases you must provide the state transition graph and simulate the FSA. 
For 1 (e) you can use the alphabet 0, 1, 2, 3,...,7 treating each of the 
column vector as a binary number where you read it from top to bottom. For 
example  0 corresponds to 011 or 3.
         1
         1

ASSOCIATIVITY PROBLEM: Give a non-deterministic finite automaton that 
accepts all strings over the alphabet {a, b, c} that have the same value 
when evaluated left to right as right to left using the following table:

       a b c
      -------
   a | a a c
   b | c a b
   c | b c a

For example, abc evaluated left-to-right gives ac which gives c. abc 
evaluated right to left gives ab which gives a. Thus, your machine must 
reject abc. On the other hand, aaa gives a regardless of the direction 
that you use. Thus, your machine must accept aaa. Be sure to run your 
solution on the NDFA simulator you wrote as the first exercise for this 
problem set. Submit sample runs of your solution with the homework.