; EXAMPLE 1:
; Turing machine for recognizing a^nb^n
; halting for grammatical strings
0 a _ r 1
1 a a r 1
1 b b r 1
1 _ _ l 2
2 b _ l 3
3 b b l 3
3 a a l 3
3 _ _ r 0
; not grammatical over {a,b} --> infinite loop
0 b b l 1
2 _ _ l 2
2 a a r 2


; EXAMPLE 2:
; Turing machine for generating a^nb^n by function f: f(n) = a^nb^n
0 1 a r 1
1 1 1 r 1
1 _ b l 2
2 1 1 l 2
2 b b l 2
2 a a r 0
1 b b r 1