title 
Universal Turing Machine

description
A 24-state Univeral Turing Machine.  The left end of the tape 
(up to the first y) is the input/output area, and the right 
end is the machine description. 'm' marks the current tape position. 
Note that the I/O tape doesnot extend infinitely to the right, 
only to the left. Between the first y and the first x is the current 
state (in binary) followed by the symbol on the current tape cell (0 or 1). 
The machine description is a list of transitions, separated by the character x 
(the final transition is followed by a y).  Each transition is written as 
{old state, old symbol, new state, new symbol, direction (0 for left, 1 for right).} 
So, for instance: 
"x 0 1 1 1 1 0 1 x" 
means "If the current state is 1 and the current symbol is 1, 
go to state 3, write 0, and shift right.  Each state must use the same number 
of binary digits, and the area between the first y and the fist x must be the length 
of a state name + 1 (to hold the current symbol).  The default 
symbol for new tape cells is 0 for this machine. The UTM halts if it encounters 
a state-symbol pair that is not listed in the machine description (So, 
to create a halt state, create a state with no transitions coming out of it.) 
This UTM includes one tape, which programs the binary counter.

fill symbol
0


vertices
1 L 0.4 0.2
2 R 0.2 0.2
3 R 0.1 0.6
4 R 0.2 0.8
5 R 0.3 0.6
6 L 0.2 0.4

7 R 0.4 0.8
8 L 0.5 0.7
9 L 0.5 0.9
10 R 0.6 0.7
11 R 0.6 0.9
12 R 0.7 0.8

13 L 0.8 0.7
14 L 0.8 0.9
15 R 0.9 0.8
16 R 0.9 0.5
17 L 0.9 0.2

18 L 0.7 0.3
19 L 0.7 0.1
20 R 0.6 0.3
21 L 0.6 0.1
22 R 0.5 0.3
23 R 0.5 0.1

24 H 0.3 0.3

edges
1 1 0 a 90
1 1 1 b -135
1 4 y y 0.6
2 1 x x 0.2
2 24 y y
3 2 1 b
3 6 0 a
4 3 a 0
4 5 b 1
4 7 x x
5 2 0 a
5 6 1 b
6 4 y y

7 8 1 b
7 9 0 a
8 10 y y
9 11 y y
10 12 0 b
10 12 1 b
10 13 x x
11 12 0 a
11 12 1 a
11 14 x x
12 7 x x

13 15 m b
14 15 m a
15 15 b 1 30
15 15 a 0 -90
15 16 x x 
16 17 1 1 0.2
16 17 0 0 -0.2
17 17 b 1 90
17 17 a 0
17 18 0 s
17 19 1 s

18 20 b 0 
18 21 a 0 0.4
19 20 b 1 0.4
19 21 a 1
20 22 0 m
20 23 1 m 0.4
21 22 0 m 0.4
21 23 1 m
22 1 s a
23 1 s b

tapes
//binary counter
0 0 0 m 0 0 0 y 0 [1] x 0 0 0 0 1 x 0 1 1 1 0 x 1 0 0 1 1 x 1 1 1 0 0 y

//parity detector
//m 0 1 1 y 0 0 [1] x 0 0 0 0 0 0 1 x 0 0 1 0 1 1 1 x 0 0 y 1 0 1 1 x 0 1 0 0 1 0 1 x 0 1 1 0 1 0 1 x 0 1 y 1 0 0 1 y