#Solution to Problem 1(a) on Assignment 2.  Determine if the input has the form w#w
#where w is a string over {a,b}
#The idea is to repeatedly cross off the first non-crossed-out letter in the input and remember it,
#then scan right to the #, right to the next non-crossed-out symbol, and if it matches the remembered
#letter, cross it out.  
#When the first non-crossed out symbol is #, the next must be blank, and we accept.
#State 0 : skip Xs and look for a,b or #
0	X	0	X	R
0	a	1	X	R
0	b	2	X	R
0	#	5	#	R
#State 1: found a, look for #
1	a	1	a	R
1	b	1	b	R
1	#	3	#	R
#State 2: found b look for #
2	a	2	a	R
2	b	2	b	R
2	#	4	#	R
#State 3: look for matching a
3	X	3	X	R
3	a	6	X	L
#State 4: Look for matching b
4	X	4	X	R
4	b	6	X	L
#State 6, Head back to start
6	a	6	a	L
6	b	6	b	L
6	X	6	X	L
6	#	6	#	L
6	B	0	B	R
#State 5:  All left-hand symbols have been crossed out, verify
5	X	5	X	R
5	B	-1	B	R
#there are no un-crossed-out letters on right.